<?xml version="1.0" encoding="US-ASCII"?>
<!--XBRL Document Created with Wdesk from Workiva-->
<!-- -->
<link:linkbase xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd" xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <link:roleRef roleURI="http://www.mistrasgroup.com/role/AccountsReceivableNet" xlink:href="mg-20180930.xsd#AccountsReceivableNet" xlink:type="simple" />
  <link:roleRef roleURI="http://www.mistrasgroup.com/role/AccountsReceivableNetDetails" xlink:href="mg-20180930.xsd#AccountsReceivableNetDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.mistrasgroup.com/role/AccountsReceivableNetTables" xlink:href="mg-20180930.xsd#AccountsReceivableNetTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.mistrasgroup.com/role/AccruedExpensesAndOtherCurrentLiabilities" xlink:href="mg-20180930.xsd#AccruedExpensesAndOtherCurrentLiabilities" xlink:type="simple" />
  <link:roleRef roleURI="http://www.mistrasgroup.com/role/AccruedExpensesAndOtherCurrentLiabilitiesDetails" xlink:href="mg-20180930.xsd#AccruedExpensesAndOtherCurrentLiabilitiesDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.mistrasgroup.com/role/AccruedExpensesAndOtherCurrentLiabilitiesTables" xlink:href="mg-20180930.xsd#AccruedExpensesAndOtherCurrentLiabilitiesTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.mistrasgroup.com/role/Acquisitions" xlink:href="mg-20180930.xsd#Acquisitions" xlink:type="simple" />
  <link:roleRef roleURI="http://www.mistrasgroup.com/role/AcquisitionsAcquisitionRelatedExpenseDetails" xlink:href="mg-20180930.xsd#AcquisitionsAcquisitionRelatedExpenseDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.mistrasgroup.com/role/AcquisitionsDetails" xlink:href="mg-20180930.xsd#AcquisitionsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.mistrasgroup.com/role/AcquisitionsDispositionsDetails" xlink:href="mg-20180930.xsd#AcquisitionsDispositionsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.mistrasgroup.com/role/AcquisitionsTables" xlink:href="mg-20180930.xsd#AcquisitionsTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.mistrasgroup.com/role/CommitmentsAndContingencies" xlink:href="mg-20180930.xsd#CommitmentsAndContingencies" xlink:type="simple" />
  <link:roleRef roleURI="http://www.mistrasgroup.com/role/CommitmentsAndContingenciesDetails" xlink:href="mg-20180930.xsd#CommitmentsAndContingenciesDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.mistrasgroup.com/role/CondensedConsolidatedBalanceSheets" xlink:href="mg-20180930.xsd#CondensedConsolidatedBalanceSheets" xlink:type="simple" />
  <link:roleRef roleURI="http://www.mistrasgroup.com/role/CondensedConsolidatedBalanceSheetsParenthetical" xlink:href="mg-20180930.xsd#CondensedConsolidatedBalanceSheetsParenthetical" xlink:type="simple" />
  <link:roleRef roleURI="http://www.mistrasgroup.com/role/DescriptionOfBusinessandBasisOfPresentation" xlink:href="mg-20180930.xsd#DescriptionOfBusinessandBasisOfPresentation" xlink:type="simple" />
  <link:roleRef roleURI="http://www.mistrasgroup.com/role/DescriptionOfBusinessandBasisOfPresentationDetails" xlink:href="mg-20180930.xsd#DescriptionOfBusinessandBasisOfPresentationDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.mistrasgroup.com/role/DescriptionOfBusinessandBasisOfPresentationPolicies" xlink:href="mg-20180930.xsd#DescriptionOfBusinessandBasisOfPresentationPolicies" xlink:type="simple" />
  <link:roleRef roleURI="http://www.mistrasgroup.com/role/DocumentAndEntityInformation" xlink:href="mg-20180930.xsd#DocumentAndEntityInformation" xlink:type="simple" />
  <link:roleRef roleURI="http://www.mistrasgroup.com/role/EarningsPerShare" xlink:href="mg-20180930.xsd#EarningsPerShare" xlink:type="simple" />
  <link:roleRef roleURI="http://www.mistrasgroup.com/role/EarningsPerShareDetails" xlink:href="mg-20180930.xsd#EarningsPerShareDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.mistrasgroup.com/role/EarningsPerShareTables" xlink:href="mg-20180930.xsd#EarningsPerShareTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.mistrasgroup.com/role/FairValueMeasurements" xlink:href="mg-20180930.xsd#FairValueMeasurements" xlink:type="simple" />
  <link:roleRef roleURI="http://www.mistrasgroup.com/role/FairValueMeasurementsDetails" xlink:href="mg-20180930.xsd#FairValueMeasurementsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.mistrasgroup.com/role/FairValueMeasurementsTables" xlink:href="mg-20180930.xsd#FairValueMeasurementsTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.mistrasgroup.com/role/Goodwill" xlink:href="mg-20180930.xsd#Goodwill" xlink:type="simple" />
  <link:roleRef roleURI="http://www.mistrasgroup.com/role/GoodwillAdditionalInformationDetails" xlink:href="mg-20180930.xsd#GoodwillAdditionalInformationDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.mistrasgroup.com/role/GoodwillDetails" xlink:href="mg-20180930.xsd#GoodwillDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.mistrasgroup.com/role/GoodwillTables" xlink:href="mg-20180930.xsd#GoodwillTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.mistrasgroup.com/role/IntangibleAssets" xlink:href="mg-20180930.xsd#IntangibleAssets" xlink:type="simple" />
  <link:roleRef roleURI="http://www.mistrasgroup.com/role/IntangibleAssetsDetails" xlink:href="mg-20180930.xsd#IntangibleAssetsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.mistrasgroup.com/role/IntangibleAssetsTables" xlink:href="mg-20180930.xsd#IntangibleAssetsTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.mistrasgroup.com/role/LongTermDebt" xlink:href="mg-20180930.xsd#LongTermDebt" xlink:type="simple" />
  <link:roleRef roleURI="http://www.mistrasgroup.com/role/LongTermDebtAdditionalInformationDetails" xlink:href="mg-20180930.xsd#LongTermDebtAdditionalInformationDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.mistrasgroup.com/role/LongTermDebtScheduleOfLongTermDebtDetails" xlink:href="mg-20180930.xsd#LongTermDebtScheduleOfLongTermDebtDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.mistrasgroup.com/role/LongTermDebtTables" xlink:href="mg-20180930.xsd#LongTermDebtTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.mistrasgroup.com/role/PropertyPlantAndEquipmentNet" xlink:href="mg-20180930.xsd#PropertyPlantAndEquipmentNet" xlink:type="simple" />
  <link:roleRef roleURI="http://www.mistrasgroup.com/role/PropertyPlantAndEquipmentNetDetails" xlink:href="mg-20180930.xsd#PropertyPlantAndEquipmentNetDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.mistrasgroup.com/role/PropertyPlantAndEquipmentNetTables" xlink:href="mg-20180930.xsd#PropertyPlantAndEquipmentNetTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.mistrasgroup.com/role/RepurchaseOfCommonStock" xlink:href="mg-20180930.xsd#RepurchaseOfCommonStock" xlink:type="simple" />
  <link:roleRef roleURI="http://www.mistrasgroup.com/role/RepurchaseOfCommonStockDetails" xlink:href="mg-20180930.xsd#RepurchaseOfCommonStockDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.mistrasgroup.com/role/Revenue" xlink:href="mg-20180930.xsd#Revenue" xlink:type="simple" />
  <link:roleRef roleURI="http://www.mistrasgroup.com/role/RevenueAdditionalInformationDetails" xlink:href="mg-20180930.xsd#RevenueAdditionalInformationDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.mistrasgroup.com/role/RevenueDisaggregationOfRevenuesDetails" xlink:href="mg-20180930.xsd#RevenueDisaggregationOfRevenuesDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.mistrasgroup.com/role/RevenueTables" xlink:href="mg-20180930.xsd#RevenueTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.mistrasgroup.com/role/SegmentDisclosure" xlink:href="mg-20180930.xsd#SegmentDisclosure" xlink:type="simple" />
  <link:roleRef roleURI="http://www.mistrasgroup.com/role/SegmentDisclosureFinancialInformationBySegmentDetails" xlink:href="mg-20180930.xsd#SegmentDisclosureFinancialInformationBySegmentDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.mistrasgroup.com/role/SegmentDisclosureRevenuesByGeographicAreaDetails" xlink:href="mg-20180930.xsd#SegmentDisclosureRevenuesByGeographicAreaDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.mistrasgroup.com/role/SegmentDisclosureTables" xlink:href="mg-20180930.xsd#SegmentDisclosureTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.mistrasgroup.com/role/ShareBasedCompensation" xlink:href="mg-20180930.xsd#ShareBasedCompensation" xlink:type="simple" />
  <link:roleRef roleURI="http://www.mistrasgroup.com/role/ShareBasedCompensationEquityIncentivePlansDetails" xlink:href="mg-20180930.xsd#ShareBasedCompensationEquityIncentivePlansDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.mistrasgroup.com/role/ShareBasedCompensationPerformanceRestrictedStockUnitsActivityDetails" xlink:href="mg-20180930.xsd#ShareBasedCompensationPerformanceRestrictedStockUnitsActivityDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.mistrasgroup.com/role/ShareBasedCompensationPerformanceRestrictedStockUnitsNarrativeDetails" xlink:href="mg-20180930.xsd#ShareBasedCompensationPerformanceRestrictedStockUnitsNarrativeDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.mistrasgroup.com/role/ShareBasedCompensationRestrictedStockUnitAwardsNarrativeDetails" xlink:href="mg-20180930.xsd#ShareBasedCompensationRestrictedStockUnitAwardsNarrativeDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.mistrasgroup.com/role/ShareBasedCompensationRestrictedStockUnitsAwardsActivityDetails" xlink:href="mg-20180930.xsd#ShareBasedCompensationRestrictedStockUnitsAwardsActivityDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.mistrasgroup.com/role/ShareBasedCompensationStockOptionsDetails" xlink:href="mg-20180930.xsd#ShareBasedCompensationStockOptionsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.mistrasgroup.com/role/ShareBasedCompensationTables" xlink:href="mg-20180930.xsd#ShareBasedCompensationTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.mistrasgroup.com/role/UnauditedCondensedConsolidatedStatementsOfCashFlows" xlink:href="mg-20180930.xsd#UnauditedCondensedConsolidatedStatementsOfCashFlows" xlink:type="simple" />
  <link:roleRef roleURI="http://www.mistrasgroup.com/role/UnauditedCondensedConsolidatedStatementsOfComprehensiveIncomeLoss" xlink:href="mg-20180930.xsd#UnauditedCondensedConsolidatedStatementsOfComprehensiveIncomeLoss" xlink:type="simple" />
  <link:roleRef roleURI="http://www.mistrasgroup.com/role/UnauditedCondensedConsolidatedStatementsOfIncomeLoss" xlink:href="mg-20180930.xsd#UnauditedCondensedConsolidatedStatementsOfIncomeLoss" xlink:type="simple" />
  <link:calculationLink xlink:role="http://www.mistrasgroup.com/role/AccountsReceivableNet" xlink:type="extended" />
  <link:calculationLink xlink:role="http://www.mistrasgroup.com/role/AccountsReceivableNetDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ReceivablesNetCurrent" xlink:label="loc_us-gaap_ReceivablesNetCurrent_418195A2C97A53BE8AD207C390C665EF" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AccountsReceivableGrossCurrent" xlink:label="loc_us-gaap_AccountsReceivableGrossCurrent_71F91CECE8D253BCA85E030F012F69CC" xlink:type="locator" />
    <link:calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_ReceivablesNetCurrent_418195A2C97A53BE8AD207C390C665EF" xlink:to="loc_us-gaap_AccountsReceivableGrossCurrent_71F91CECE8D253BCA85E030F012F69CC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent" xlink:label="loc_us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent_0E79DB441B0F5DE088EBB43017D2F4CF" xlink:type="locator" />
    <link:calculationArc order="2" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_ReceivablesNetCurrent_418195A2C97A53BE8AD207C390C665EF" xlink:to="loc_us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent_0E79DB441B0F5DE088EBB43017D2F4CF" xlink:type="arc" />
  </link:calculationLink>
  <link:calculationLink xlink:role="http://www.mistrasgroup.com/role/AccountsReceivableNetTables" xlink:type="extended" />
  <link:calculationLink xlink:role="http://www.mistrasgroup.com/role/AccruedExpensesAndOtherCurrentLiabilities" xlink:type="extended" />
  <link:calculationLink xlink:role="http://www.mistrasgroup.com/role/AccruedExpensesAndOtherCurrentLiabilitiesDetails" xlink:type="extended">
    <link:loc xlink:href="mg-20180930.xsd#mg_AccruedLiabilitiesDeferredRevenuesAndContingentConsiderationLiabilitiesCurrent" xlink:label="loc_mg_AccruedLiabilitiesDeferredRevenuesAndContingentConsiderationLiabilitiesCurrent_7311c7a7-4f0f-4e7b-b347-7e1eb604df22" xlink:type="locator" />
    <link:loc xlink:href="mg-20180930.xsd#mg_AccruedSalariesWagesAndEmployeeRelatedBenefitsCurrent" xlink:label="loc_mg_AccruedSalariesWagesAndEmployeeRelatedBenefitsCurrent_54dde219-2343-0999-703f-7e1eb5d5a75a" xlink:type="locator" />
    <link:calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_mg_AccruedLiabilitiesDeferredRevenuesAndContingentConsiderationLiabilitiesCurrent_7311c7a7-4f0f-4e7b-b347-7e1eb604df22" xlink:to="loc_mg_AccruedSalariesWagesAndEmployeeRelatedBenefitsCurrent_54dde219-2343-0999-703f-7e1eb5d5a75a" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BusinessCombinationContingentConsiderationLiabilityCurrent" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationLiabilityCurrent_0a95dc2d-3528-07ba-a167-5f0b147c1e5d" xlink:type="locator" />
    <link:calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_mg_AccruedLiabilitiesDeferredRevenuesAndContingentConsiderationLiabilitiesCurrent_7311c7a7-4f0f-4e7b-b347-7e1eb604df22" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationLiabilityCurrent_0a95dc2d-3528-07ba-a167-5f0b147c1e5d" xlink:type="arc" />
    <link:loc xlink:href="mg-20180930.xsd#mg_AccruedWorkersCompensationAndHealthBenefitsCurrent" xlink:label="loc_mg_AccruedWorkersCompensationAndHealthBenefitsCurrent_d0308988-247d-661f-444c-7e1eb5e5ba80" xlink:type="locator" />
    <link:calculationArc order="3" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_mg_AccruedLiabilitiesDeferredRevenuesAndContingentConsiderationLiabilitiesCurrent_7311c7a7-4f0f-4e7b-b347-7e1eb604df22" xlink:to="loc_mg_AccruedWorkersCompensationAndHealthBenefitsCurrent_d0308988-247d-661f-444c-7e1eb5e5ba80" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ContractWithCustomerLiabilityCurrent" xlink:label="loc_us-gaap_ContractWithCustomerLiabilityCurrent_06a8bc6d-0a67-7d01-441e-cd6865c4697c" xlink:type="locator" />
    <link:calculationArc order="4" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_mg_AccruedLiabilitiesDeferredRevenuesAndContingentConsiderationLiabilitiesCurrent_7311c7a7-4f0f-4e7b-b347-7e1eb604df22" xlink:to="loc_us-gaap_ContractWithCustomerLiabilityCurrent_06a8bc6d-0a67-7d01-441e-cd6865c4697c" xlink:type="arc" />
    <link:loc xlink:href="mg-20180930.xsd#mg_LegalSettlementLiabilitiesCurrent" xlink:label="loc_mg_LegalSettlementLiabilitiesCurrent_DED858A2DE9B480B8689B6B2B8878CD2" xlink:type="locator" />
    <link:calculationArc order="5" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_mg_AccruedLiabilitiesDeferredRevenuesAndContingentConsiderationLiabilitiesCurrent_7311c7a7-4f0f-4e7b-b347-7e1eb604df22" xlink:to="loc_mg_LegalSettlementLiabilitiesCurrent_DED858A2DE9B480B8689B6B2B8878CD2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LossContingencyAccrualCarryingValueCurrent" xlink:label="loc_us-gaap_LossContingencyAccrualCarryingValueCurrent_a7f87e34-36d7-267d-2d53-3177045ba4ef" xlink:type="locator" />
    <link:calculationArc order="6" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_mg_AccruedLiabilitiesDeferredRevenuesAndContingentConsiderationLiabilitiesCurrent_7311c7a7-4f0f-4e7b-b347-7e1eb604df22" xlink:to="loc_us-gaap_LossContingencyAccrualCarryingValueCurrent_a7f87e34-36d7-267d-2d53-3177045ba4ef" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OtherAccruedLiabilitiesCurrent" xlink:label="loc_us-gaap_OtherAccruedLiabilitiesCurrent_00b000cf-7f1d-4891-7244-daf9f6335db0" xlink:type="locator" />
    <link:calculationArc order="7" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_mg_AccruedLiabilitiesDeferredRevenuesAndContingentConsiderationLiabilitiesCurrent_7311c7a7-4f0f-4e7b-b347-7e1eb604df22" xlink:to="loc_us-gaap_OtherAccruedLiabilitiesCurrent_00b000cf-7f1d-4891-7244-daf9f6335db0" xlink:type="arc" />
  </link:calculationLink>
  <link:calculationLink xlink:role="http://www.mistrasgroup.com/role/AccruedExpensesAndOtherCurrentLiabilitiesTables" xlink:type="extended" />
  <link:calculationLink xlink:role="http://www.mistrasgroup.com/role/Acquisitions" xlink:type="extended" />
  <link:calculationLink xlink:role="http://www.mistrasgroup.com/role/AcquisitionsAcquisitionRelatedExpenseDetails" xlink:type="extended">
    <link:loc xlink:href="mg-20180930.xsd#mg_AcquisitionRelatedCostsAndFairValueAdjustmentsToInitialPurchasePriceAllocation" xlink:label="loc_mg_AcquisitionRelatedCostsAndFairValueAdjustmentsToInitialPurchasePriceAllocation_82A67D60FD905C649A491D8BBC4724AA" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BusinessCombinationAcquisitionRelatedCosts" xlink:label="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_83C52A84A8F05831B36A10C3E4189AD1" xlink:type="locator" />
    <link:calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_mg_AcquisitionRelatedCostsAndFairValueAdjustmentsToInitialPurchasePriceAllocation_82A67D60FD905C649A491D8BBC4724AA" xlink:to="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_83C52A84A8F05831B36A10C3E4189AD1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1_192AB5E2C4095098B7E9596CBBA3E566" xlink:type="locator" />
    <link:calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_mg_AcquisitionRelatedCostsAndFairValueAdjustmentsToInitialPurchasePriceAllocation_82A67D60FD905C649A491D8BBC4724AA" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1_192AB5E2C4095098B7E9596CBBA3E566" xlink:type="arc" />
  </link:calculationLink>
  <link:calculationLink xlink:role="http://www.mistrasgroup.com/role/AcquisitionsDetails" xlink:type="extended" />
  <link:calculationLink xlink:role="http://www.mistrasgroup.com/role/AcquisitionsDispositionsDetails" xlink:type="extended" />
  <link:calculationLink xlink:role="http://www.mistrasgroup.com/role/AcquisitionsTables" xlink:type="extended" />
  <link:calculationLink xlink:role="http://www.mistrasgroup.com/role/CommitmentsAndContingencies" xlink:type="extended" />
  <link:calculationLink xlink:role="http://www.mistrasgroup.com/role/CommitmentsAndContingenciesDetails" xlink:type="extended" />
  <link:calculationLink xlink:role="http://www.mistrasgroup.com/role/CondensedConsolidatedBalanceSheets" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquity" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquity_159dcb00-b17e-17db-7098-be4159799459" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_Liabilities" xlink:label="loc_us-gaap_Liabilities_d8bb821f-d155-9d4e-1738-736b4bf4cb19" xlink:type="locator" />
    <link:calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquity_159dcb00-b17e-17db-7098-be4159799459" xlink:to="loc_us-gaap_Liabilities_d8bb821f-d155-9d4e-1738-736b4bf4cb19" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LiabilitiesCurrent" xlink:label="loc_us-gaap_LiabilitiesCurrent_f5e246cf-e80f-d00b-c8ed-4796aa2df4b4" xlink:type="locator" />
    <link:calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_d8bb821f-d155-9d4e-1738-736b4bf4cb19" xlink:to="loc_us-gaap_LiabilitiesCurrent_f5e246cf-e80f-d00b-c8ed-4796aa2df4b4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AccountsPayableCurrent" xlink:label="loc_us-gaap_AccountsPayableCurrent_7a72b51a-735c-1ad4-bd3f-d9bcf2d6a26d" xlink:type="locator" />
    <link:calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesCurrent_f5e246cf-e80f-d00b-c8ed-4796aa2df4b4" xlink:to="loc_us-gaap_AccountsPayableCurrent_7a72b51a-735c-1ad4-bd3f-d9bcf2d6a26d" xlink:type="arc" />
    <link:loc xlink:href="mg-20180930.xsd#mg_AccruedLiabilitiesDeferredRevenuesAndContingentConsiderationLiabilitiesCurrent" xlink:label="loc_mg_AccruedLiabilitiesDeferredRevenuesAndContingentConsiderationLiabilitiesCurrent_7311c7a7-4f0f-4e7b-b347-7e1eb604df22" xlink:type="locator" />
    <link:calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesCurrent_f5e246cf-e80f-d00b-c8ed-4796aa2df4b4" xlink:to="loc_mg_AccruedLiabilitiesDeferredRevenuesAndContingentConsiderationLiabilitiesCurrent_7311c7a7-4f0f-4e7b-b347-7e1eb604df22" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LongTermDebtCurrent" xlink:label="loc_us-gaap_LongTermDebtCurrent_f61bf97e-c3a5-ba72-7591-eba8e7bb6a44" xlink:type="locator" />
    <link:calculationArc order="3" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesCurrent_f5e246cf-e80f-d00b-c8ed-4796aa2df4b4" xlink:to="loc_us-gaap_LongTermDebtCurrent_f61bf97e-c3a5-ba72-7591-eba8e7bb6a44" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CapitalLeaseObligationsCurrent" xlink:label="loc_us-gaap_CapitalLeaseObligationsCurrent_76865e4e-2049-cac6-edec-da1c3f948f32" xlink:type="locator" />
    <link:calculationArc order="4" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesCurrent_f5e246cf-e80f-d00b-c8ed-4796aa2df4b4" xlink:to="loc_us-gaap_CapitalLeaseObligationsCurrent_76865e4e-2049-cac6-edec-da1c3f948f32" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AccruedIncomeTaxesCurrent" xlink:label="loc_us-gaap_AccruedIncomeTaxesCurrent_bd3a7ae4-0e62-b7df-2312-729d1644863d" xlink:type="locator" />
    <link:calculationArc order="5" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesCurrent_f5e246cf-e80f-d00b-c8ed-4796aa2df4b4" xlink:to="loc_us-gaap_AccruedIncomeTaxesCurrent_bd3a7ae4-0e62-b7df-2312-729d1644863d" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LongTermDebtNoncurrent" xlink:label="loc_us-gaap_LongTermDebtNoncurrent_822b66ff-44a1-e66b-5e0c-09356970a23d" xlink:type="locator" />
    <link:calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_d8bb821f-d155-9d4e-1738-736b4bf4cb19" xlink:to="loc_us-gaap_LongTermDebtNoncurrent_822b66ff-44a1-e66b-5e0c-09356970a23d" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CapitalLeaseObligationsNoncurrent" xlink:label="loc_us-gaap_CapitalLeaseObligationsNoncurrent_efe2512e-d4d4-64d6-9c0d-99078496415f" xlink:type="locator" />
    <link:calculationArc order="3" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_d8bb821f-d155-9d4e-1738-736b4bf4cb19" xlink:to="loc_us-gaap_CapitalLeaseObligationsNoncurrent_efe2512e-d4d4-64d6-9c0d-99078496415f" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DeferredIncomeTaxLiabilitiesNet" xlink:label="loc_us-gaap_DeferredIncomeTaxLiabilitiesNet_9a73c768-7e07-f56f-7aba-2b93110d3715" xlink:type="locator" />
    <link:calculationArc order="4" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_d8bb821f-d155-9d4e-1738-736b4bf4cb19" xlink:to="loc_us-gaap_DeferredIncomeTaxLiabilitiesNet_9a73c768-7e07-f56f-7aba-2b93110d3715" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OtherLiabilitiesNoncurrent" xlink:label="loc_us-gaap_OtherLiabilitiesNoncurrent_f234998c-5e05-09d0-d53e-5c44423c97c0" xlink:type="locator" />
    <link:calculationArc order="5" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_d8bb821f-d155-9d4e-1738-736b4bf4cb19" xlink:to="loc_us-gaap_OtherLiabilitiesNoncurrent_f234998c-5e05-09d0-d53e-5c44423c97c0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_00443492-92dd-7fc1-13b6-792f3e163e73" xlink:type="locator" />
    <link:calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquity_159dcb00-b17e-17db-7098-be4159799459" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_00443492-92dd-7fc1-13b6-792f3e163e73" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StockholdersEquity" xlink:label="loc_us-gaap_StockholdersEquity_4b158f76-5f04-5e4d-ead3-d80e1f9943db" xlink:type="locator" />
    <link:calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_00443492-92dd-7fc1-13b6-792f3e163e73" xlink:to="loc_us-gaap_StockholdersEquity_4b158f76-5f04-5e4d-ead3-d80e1f9943db" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PreferredStockValue" xlink:label="loc_us-gaap_PreferredStockValue_4fb6195d-d905-dac7-e5a0-79f324993f79" xlink:type="locator" />
    <link:calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_4b158f76-5f04-5e4d-ead3-d80e1f9943db" xlink:to="loc_us-gaap_PreferredStockValue_4fb6195d-d905-dac7-e5a0-79f324993f79" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CommonStockValue" xlink:label="loc_us-gaap_CommonStockValue_c3f7606a-e7e9-61d5-b60b-b4b059f68b26" xlink:type="locator" />
    <link:calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_4b158f76-5f04-5e4d-ead3-d80e1f9943db" xlink:to="loc_us-gaap_CommonStockValue_c3f7606a-e7e9-61d5-b60b-b4b059f68b26" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AdditionalPaidInCapital" xlink:label="loc_us-gaap_AdditionalPaidInCapital_2d1b9d27-8b19-82d9-2843-5b3d292b7fbb" xlink:type="locator" />
    <link:calculationArc order="3" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_4b158f76-5f04-5e4d-ead3-d80e1f9943db" xlink:to="loc_us-gaap_AdditionalPaidInCapital_2d1b9d27-8b19-82d9-2843-5b3d292b7fbb" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RetainedEarningsAccumulatedDeficit" xlink:label="loc_us-gaap_RetainedEarningsAccumulatedDeficit_065cb284-7fca-cc9b-5752-2feaf74d0011" xlink:type="locator" />
    <link:calculationArc order="4" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_4b158f76-5f04-5e4d-ead3-d80e1f9943db" xlink:to="loc_us-gaap_RetainedEarningsAccumulatedDeficit_065cb284-7fca-cc9b-5752-2feaf74d0011" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_04f0961a-a0bc-88cf-6658-3f950da4a458" xlink:type="locator" />
    <link:calculationArc order="5" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_4b158f76-5f04-5e4d-ead3-d80e1f9943db" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_04f0961a-a0bc-88cf-6658-3f950da4a458" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_MinorityInterest" xlink:label="loc_us-gaap_MinorityInterest_cb565c4d-35c2-d825-4672-f1619e51c133" xlink:type="locator" />
    <link:calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_00443492-92dd-7fc1-13b6-792f3e163e73" xlink:to="loc_us-gaap_MinorityInterest_cb565c4d-35c2-d825-4672-f1619e51c133" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CommitmentsAndContingencies" xlink:label="loc_us-gaap_CommitmentsAndContingencies_058e01e4-b9a1-623e-29f5-1b5c79bf095a" xlink:type="locator" />
    <link:calculationArc order="3" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquity_159dcb00-b17e-17db-7098-be4159799459" xlink:to="loc_us-gaap_CommitmentsAndContingencies_058e01e4-b9a1-623e-29f5-1b5c79bf095a" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_Assets" xlink:label="loc_us-gaap_Assets_c6057b1d-6685-8249-2051-6c57f3a16a9e" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AssetsCurrent" xlink:label="loc_us-gaap_AssetsCurrent_8a47066b-3628-88d1-49db-ed09aecc7fc7" xlink:type="locator" />
    <link:calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_c6057b1d-6685-8249-2051-6c57f3a16a9e" xlink:to="loc_us-gaap_AssetsCurrent_8a47066b-3628-88d1-49db-ed09aecc7fc7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:label="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_07da1db4-2708-4446-4250-1fdd5956185e" xlink:type="locator" />
    <link:calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsCurrent_8a47066b-3628-88d1-49db-ed09aecc7fc7" xlink:to="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_07da1db4-2708-4446-4250-1fdd5956185e" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ReceivablesNetCurrent" xlink:label="loc_us-gaap_ReceivablesNetCurrent_4261eb63-a0fe-7be1-e8a2-dcf5644ff056" xlink:type="locator" />
    <link:calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsCurrent_8a47066b-3628-88d1-49db-ed09aecc7fc7" xlink:to="loc_us-gaap_ReceivablesNetCurrent_4261eb63-a0fe-7be1-e8a2-dcf5644ff056" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_InventoryNet" xlink:label="loc_us-gaap_InventoryNet_7eab44cf-1ea1-ca2a-420f-21f7b5343fc3" xlink:type="locator" />
    <link:calculationArc order="3" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsCurrent_8a47066b-3628-88d1-49db-ed09aecc7fc7" xlink:to="loc_us-gaap_InventoryNet_7eab44cf-1ea1-ca2a-420f-21f7b5343fc3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PrepaidExpenseAndOtherAssetsCurrent" xlink:label="loc_us-gaap_PrepaidExpenseAndOtherAssetsCurrent_2294e6a2-7bab-43ed-d02c-bdf73b8fa561" xlink:type="locator" />
    <link:calculationArc order="4" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsCurrent_8a47066b-3628-88d1-49db-ed09aecc7fc7" xlink:to="loc_us-gaap_PrepaidExpenseAndOtherAssetsCurrent_2294e6a2-7bab-43ed-d02c-bdf73b8fa561" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_1944a381-5c4e-ce3c-9111-13ccd1c639db" xlink:type="locator" />
    <link:calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_c6057b1d-6685-8249-2051-6c57f3a16a9e" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_1944a381-5c4e-ce3c-9111-13ccd1c639db" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:label="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_1fe06082-076b-052d-6e2e-930afe9d6b2d" xlink:type="locator" />
    <link:calculationArc order="3" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_c6057b1d-6685-8249-2051-6c57f3a16a9e" xlink:to="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_1fe06082-076b-052d-6e2e-930afe9d6b2d" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_Goodwill" xlink:label="loc_us-gaap_Goodwill_93a64cae-271a-5e6b-8c83-5adf9f941142" xlink:type="locator" />
    <link:calculationArc order="4" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_c6057b1d-6685-8249-2051-6c57f3a16a9e" xlink:to="loc_us-gaap_Goodwill_93a64cae-271a-5e6b-8c83-5adf9f941142" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DeferredIncomeTaxAssetsNet" xlink:label="loc_us-gaap_DeferredIncomeTaxAssetsNet_0c301281-b140-dfcb-9991-ae503484f9da" xlink:type="locator" />
    <link:calculationArc order="5" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_c6057b1d-6685-8249-2051-6c57f3a16a9e" xlink:to="loc_us-gaap_DeferredIncomeTaxAssetsNet_0c301281-b140-dfcb-9991-ae503484f9da" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OtherAssetsNoncurrent" xlink:label="loc_us-gaap_OtherAssetsNoncurrent_9b27fab9-d497-627b-4cfb-6b585220b978" xlink:type="locator" />
    <link:calculationArc order="6" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_c6057b1d-6685-8249-2051-6c57f3a16a9e" xlink:to="loc_us-gaap_OtherAssetsNoncurrent_9b27fab9-d497-627b-4cfb-6b585220b978" xlink:type="arc" />
  </link:calculationLink>
  <link:calculationLink xlink:role="http://www.mistrasgroup.com/role/CondensedConsolidatedBalanceSheetsParenthetical" xlink:type="extended" />
  <link:calculationLink xlink:role="http://www.mistrasgroup.com/role/DescriptionOfBusinessandBasisOfPresentation" xlink:type="extended" />
  <link:calculationLink xlink:role="http://www.mistrasgroup.com/role/DescriptionOfBusinessandBasisOfPresentationDetails" xlink:type="extended" />
  <link:calculationLink xlink:role="http://www.mistrasgroup.com/role/DescriptionOfBusinessandBasisOfPresentationPolicies" xlink:type="extended" />
  <link:calculationLink xlink:role="http://www.mistrasgroup.com/role/DocumentAndEntityInformation" xlink:type="extended" />
  <link:calculationLink xlink:role="http://www.mistrasgroup.com/role/EarningsPerShare" xlink:type="extended" />
  <link:calculationLink xlink:role="http://www.mistrasgroup.com/role/EarningsPerShareDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding" xlink:label="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_223fd9c8-68e8-e433-7c40-f98b238e79de" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_86e61cf2-b7b2-e230-65f1-5a2b152f3a30" xlink:type="locator" />
    <link:calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_223fd9c8-68e8-e433-7c40-f98b238e79de" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_86e61cf2-b7b2-e230-65f1-5a2b152f3a30" xlink:type="arc" />
    <link:loc xlink:href="mg-20180930.xsd#mg_IncrementalCommonSharesAttributableToStockOptionsOutstanding" xlink:label="loc_mg_IncrementalCommonSharesAttributableToStockOptionsOutstanding_adc6b347-b738-b1b0-75ff-7e1eb5f48141" xlink:type="locator" />
    <link:calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_223fd9c8-68e8-e433-7c40-f98b238e79de" xlink:to="loc_mg_IncrementalCommonSharesAttributableToStockOptionsOutstanding_adc6b347-b738-b1b0-75ff-7e1eb5f48141" xlink:type="arc" />
    <link:loc xlink:href="mg-20180930.xsd#mg_IncrementalCommonSharesAttributableToRestrictedStockUnitsOutstanding" xlink:label="loc_mg_IncrementalCommonSharesAttributableToRestrictedStockUnitsOutstanding_0f2969d3-95fc-31c9-1092-7e1eb5f48019" xlink:type="locator" />
    <link:calculationArc order="3" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_223fd9c8-68e8-e433-7c40-f98b238e79de" xlink:to="loc_mg_IncrementalCommonSharesAttributableToRestrictedStockUnitsOutstanding_0f2969d3-95fc-31c9-1092-7e1eb5f48019" xlink:type="arc" />
  </link:calculationLink>
  <link:calculationLink xlink:role="http://www.mistrasgroup.com/role/EarningsPerShareTables" xlink:type="extended" />
  <link:calculationLink xlink:role="http://www.mistrasgroup.com/role/FairValueMeasurements" xlink:type="extended" />
  <link:calculationLink xlink:role="http://www.mistrasgroup.com/role/FairValueMeasurementsDetails" xlink:type="extended" />
  <link:calculationLink xlink:role="http://www.mistrasgroup.com/role/FairValueMeasurementsTables" xlink:type="extended" />
  <link:calculationLink xlink:role="http://www.mistrasgroup.com/role/Goodwill" xlink:type="extended" />
  <link:calculationLink xlink:role="http://www.mistrasgroup.com/role/GoodwillAdditionalInformationDetails" xlink:type="extended" />
  <link:calculationLink xlink:role="http://www.mistrasgroup.com/role/GoodwillDetails" xlink:type="extended" />
  <link:calculationLink xlink:role="http://www.mistrasgroup.com/role/GoodwillTables" xlink:type="extended" />
  <link:calculationLink xlink:role="http://www.mistrasgroup.com/role/IntangibleAssets" xlink:type="extended" />
  <link:calculationLink xlink:role="http://www.mistrasgroup.com/role/IntangibleAssetsDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:label="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_06DC477D07CC5C369BA73A3ED42E805A" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsGross" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsGross_4BEA541D773852938CAE2EB1BE70171D" xlink:type="locator" />
    <link:calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_06DC477D07CC5C369BA73A3ED42E805A" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsGross_4BEA541D773852938CAE2EB1BE70171D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_E0837ECC19B356089684D931D5C0A386" xlink:type="locator" />
    <link:calculationArc order="2" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_06DC477D07CC5C369BA73A3ED42E805A" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_E0837ECC19B356089684D931D5C0A386" xlink:type="arc" />
    <link:loc xlink:href="mg-20180930.xsd#mg_FiniteLivedIntangibleAssetsImpairedAccumulatedImpairmentLoss" xlink:label="loc_mg_FiniteLivedIntangibleAssetsImpairedAccumulatedImpairmentLoss_507CDDA4D15B5602BE890D8EE26DCF83" xlink:type="locator" />
    <link:calculationArc order="3" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_06DC477D07CC5C369BA73A3ED42E805A" xlink:to="loc_mg_FiniteLivedIntangibleAssetsImpairedAccumulatedImpairmentLoss_507CDDA4D15B5602BE890D8EE26DCF83" xlink:type="arc" />
  </link:calculationLink>
  <link:calculationLink xlink:role="http://www.mistrasgroup.com/role/IntangibleAssetsTables" xlink:type="extended" />
  <link:calculationLink xlink:role="http://www.mistrasgroup.com/role/LongTermDebt" xlink:type="extended" />
  <link:calculationLink xlink:role="http://www.mistrasgroup.com/role/LongTermDebtAdditionalInformationDetails" xlink:type="extended" />
  <link:calculationLink xlink:role="http://www.mistrasgroup.com/role/LongTermDebtScheduleOfLongTermDebtDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LongTermDebt" xlink:label="loc_us-gaap_LongTermDebt_4242AF3CF028596FA895B4D857165C0F" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LongTermDebtCurrent" xlink:label="loc_us-gaap_LongTermDebtCurrent_98B4669028BF59A1BF60622BEDBDB3FC" xlink:type="locator" />
    <link:calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LongTermDebt_4242AF3CF028596FA895B4D857165C0F" xlink:to="loc_us-gaap_LongTermDebtCurrent_98B4669028BF59A1BF60622BEDBDB3FC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LongTermDebtNoncurrent" xlink:label="loc_us-gaap_LongTermDebtNoncurrent_29B4B39546F45F658AA94F9F52B5C9FD" xlink:type="locator" />
    <link:calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LongTermDebt_4242AF3CF028596FA895B4D857165C0F" xlink:to="loc_us-gaap_LongTermDebtNoncurrent_29B4B39546F45F658AA94F9F52B5C9FD" xlink:type="arc" />
  </link:calculationLink>
  <link:calculationLink xlink:role="http://www.mistrasgroup.com/role/LongTermDebtTables" xlink:type="extended" />
  <link:calculationLink xlink:role="http://www.mistrasgroup.com/role/PropertyPlantAndEquipmentNet" xlink:type="extended" />
  <link:calculationLink xlink:role="http://www.mistrasgroup.com/role/PropertyPlantAndEquipmentNetDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_C1110E7C96D859D688E1E04C6FD6C2E5" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PropertyPlantAndEquipmentGross" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentGross_65E459C153E55B3586FC8E00DD7F7011" xlink:type="locator" />
    <link:calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentNet_C1110E7C96D859D688E1E04C6FD6C2E5" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentGross_65E459C153E55B3586FC8E00DD7F7011" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:label="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_389C2CEC9A105843A008C6E3F1B26884" xlink:type="locator" />
    <link:calculationArc order="2" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentNet_C1110E7C96D859D688E1E04C6FD6C2E5" xlink:to="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_389C2CEC9A105843A008C6E3F1B26884" xlink:type="arc" />
  </link:calculationLink>
  <link:calculationLink xlink:role="http://www.mistrasgroup.com/role/PropertyPlantAndEquipmentNetTables" xlink:type="extended" />
  <link:calculationLink xlink:role="http://www.mistrasgroup.com/role/RepurchaseOfCommonStock" xlink:type="extended" />
  <link:calculationLink xlink:role="http://www.mistrasgroup.com/role/RepurchaseOfCommonStockDetails" xlink:type="extended" />
  <link:calculationLink xlink:role="http://www.mistrasgroup.com/role/Revenue" xlink:type="extended" />
  <link:calculationLink xlink:role="http://www.mistrasgroup.com/role/RevenueAdditionalInformationDetails" xlink:type="extended" />
  <link:calculationLink xlink:role="http://www.mistrasgroup.com/role/RevenueDisaggregationOfRevenuesDetails" xlink:type="extended" />
  <link:calculationLink xlink:role="http://www.mistrasgroup.com/role/RevenueTables" xlink:type="extended" />
  <link:calculationLink xlink:role="http://www.mistrasgroup.com/role/SegmentDisclosure" xlink:type="extended" />
  <link:calculationLink xlink:role="http://www.mistrasgroup.com/role/SegmentDisclosureFinancialInformationBySegmentDetails" xlink:type="extended" />
  <link:calculationLink xlink:role="http://www.mistrasgroup.com/role/SegmentDisclosureRevenuesByGeographicAreaDetails" xlink:type="extended" />
  <link:calculationLink xlink:role="http://www.mistrasgroup.com/role/SegmentDisclosureTables" xlink:type="extended" />
  <link:calculationLink xlink:role="http://www.mistrasgroup.com/role/ShareBasedCompensation" xlink:type="extended" />
  <link:calculationLink xlink:role="http://www.mistrasgroup.com/role/ShareBasedCompensationEquityIncentivePlansDetails" xlink:type="extended" />
  <link:calculationLink xlink:role="http://www.mistrasgroup.com/role/ShareBasedCompensationPerformanceRestrictedStockUnitsActivityDetails" xlink:type="extended" />
  <link:calculationLink xlink:role="http://www.mistrasgroup.com/role/ShareBasedCompensationPerformanceRestrictedStockUnitsNarrativeDetails" xlink:type="extended" />
  <link:calculationLink xlink:role="http://www.mistrasgroup.com/role/ShareBasedCompensationRestrictedStockUnitAwardsNarrativeDetails" xlink:type="extended" />
  <link:calculationLink xlink:role="http://www.mistrasgroup.com/role/ShareBasedCompensationRestrictedStockUnitsAwardsActivityDetails" xlink:type="extended" />
  <link:calculationLink xlink:role="http://www.mistrasgroup.com/role/ShareBasedCompensationStockOptionsDetails" xlink:type="extended" />
  <link:calculationLink xlink:role="http://www.mistrasgroup.com/role/ShareBasedCompensationTables" xlink:type="extended" />
  <link:calculationLink xlink:role="http://www.mistrasgroup.com/role/UnauditedCondensedConsolidatedStatementsOfCashFlows" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NetCashProvidedByUsedInContinuingOperations" xlink:label="loc_us-gaap_NetCashProvidedByUsedInContinuingOperations_4adbde80-36e3-b879-a631-f0caa0dbbe76" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_444b1ac7-f47a-4ce3-0caa-537f7e4ab8c3" xlink:type="locator" />
    <link:calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInContinuingOperations_4adbde80-36e3-b879-a631-f0caa0dbbe76" xlink:to="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_444b1ac7-f47a-4ce3-0caa-537f7e4ab8c3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ProfitLoss" xlink:label="loc_us-gaap_ProfitLoss_adacf05e-7e15-bd60-3e53-87432885dc29" xlink:type="locator" />
    <link:calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_444b1ac7-f47a-4ce3-0caa-537f7e4ab8c3" xlink:to="loc_us-gaap_ProfitLoss_adacf05e-7e15-bd60-3e53-87432885dc29" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DepreciationDepletionAndAmortization" xlink:label="loc_us-gaap_DepreciationDepletionAndAmortization_37b0c31d-5d8b-0577-dfd9-aa56a79334e3" xlink:type="locator" />
    <link:calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_444b1ac7-f47a-4ce3-0caa-537f7e4ab8c3" xlink:to="loc_us-gaap_DepreciationDepletionAndAmortization_37b0c31d-5d8b-0577-dfd9-aa56a79334e3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_GoodwillAndIntangibleAssetImpairment" xlink:label="loc_us-gaap_GoodwillAndIntangibleAssetImpairment_46ff7060-620f-71f6-4d86-16b841ded8cf" xlink:type="locator" />
    <link:calculationArc order="3" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_444b1ac7-f47a-4ce3-0caa-537f7e4ab8c3" xlink:to="loc_us-gaap_GoodwillAndIntangibleAssetImpairment_46ff7060-620f-71f6-4d86-16b841ded8cf" xlink:type="arc" />
    <link:loc xlink:href="mg-20180930.xsd#mg_DeferredIncomeTaxNoncashExpenseBenefit" xlink:label="loc_mg_DeferredIncomeTaxNoncashExpenseBenefit_8ba85d53-0f5a-3b3e-cc45-7e1eb5e55e21" xlink:type="locator" />
    <link:calculationArc order="4" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_444b1ac7-f47a-4ce3-0caa-537f7e4ab8c3" xlink:to="loc_mg_DeferredIncomeTaxNoncashExpenseBenefit_8ba85d53-0f5a-3b3e-cc45-7e1eb5e55e21" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensation" xlink:label="loc_us-gaap_ShareBasedCompensation_e3eecf87-b290-4567-8a59-5b0a8e27c85b" xlink:type="locator" />
    <link:calculationArc order="5" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_444b1ac7-f47a-4ce3-0caa-537f7e4ab8c3" xlink:to="loc_us-gaap_ShareBasedCompensation_e3eecf87-b290-4567-8a59-5b0a8e27c85b" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ProvisionForDoubtfulAccounts" xlink:label="loc_us-gaap_ProvisionForDoubtfulAccounts_3bb02469-191c-4baa-c8ee-e08be21b11bb" xlink:type="locator" />
    <link:calculationArc order="6" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_444b1ac7-f47a-4ce3-0caa-537f7e4ab8c3" xlink:to="loc_us-gaap_ProvisionForDoubtfulAccounts_3bb02469-191c-4baa-c8ee-e08be21b11bb" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentFinancialLiabilities" xlink:label="loc_us-gaap_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentFinancialLiabilities_ce4837bf-30e4-df4c-0177-495529ced911" xlink:type="locator" />
    <link:calculationArc order="7" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_444b1ac7-f47a-4ce3-0caa-537f7e4ab8c3" xlink:to="loc_us-gaap_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentFinancialLiabilities_ce4837bf-30e4-df4c-0177-495529ced911" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DisposalGroupNotDiscontinuedOperationGainLossOnDisposal" xlink:label="loc_us-gaap_DisposalGroupNotDiscontinuedOperationGainLossOnDisposal_03e83c30-c623-f96c-29f8-521a710884ee" xlink:type="locator" />
    <link:calculationArc order="8" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_444b1ac7-f47a-4ce3-0caa-537f7e4ab8c3" xlink:to="loc_us-gaap_DisposalGroupNotDiscontinuedOperationGainLossOnDisposal_03e83c30-c623-f96c-29f8-521a710884ee" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OtherNoncashIncomeExpense" xlink:label="loc_us-gaap_OtherNoncashIncomeExpense_371a4d3e-148a-313f-f556-b3ca6797139e" xlink:type="locator" />
    <link:calculationArc order="9" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_444b1ac7-f47a-4ce3-0caa-537f7e4ab8c3" xlink:to="loc_us-gaap_OtherNoncashIncomeExpense_371a4d3e-148a-313f-f556-b3ca6797139e" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncreaseDecreaseInAccountsReceivable" xlink:label="loc_us-gaap_IncreaseDecreaseInAccountsReceivable_dd4bfa5e-1979-c817-e8a9-371104c0d4f7" xlink:type="locator" />
    <link:calculationArc order="10" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_444b1ac7-f47a-4ce3-0caa-537f7e4ab8c3" xlink:to="loc_us-gaap_IncreaseDecreaseInAccountsReceivable_dd4bfa5e-1979-c817-e8a9-371104c0d4f7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncreaseDecreaseInInventories" xlink:label="loc_us-gaap_IncreaseDecreaseInInventories_bf3f9720-ba63-7ecd-52ae-e754a6f349db" xlink:type="locator" />
    <link:calculationArc order="11" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_444b1ac7-f47a-4ce3-0caa-537f7e4ab8c3" xlink:to="loc_us-gaap_IncreaseDecreaseInInventories_bf3f9720-ba63-7ecd-52ae-e754a6f349db" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets" xlink:label="loc_us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_c998cbd2-a633-c2ec-1932-e3bfedecbc9f" xlink:type="locator" />
    <link:calculationArc order="12" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_444b1ac7-f47a-4ce3-0caa-537f7e4ab8c3" xlink:to="loc_us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_c998cbd2-a633-c2ec-1932-e3bfedecbc9f" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncreaseDecreaseInAccountsPayableTrade" xlink:label="loc_us-gaap_IncreaseDecreaseInAccountsPayableTrade_ed38aedf-17a0-9062-826e-1ea210c311c0" xlink:type="locator" />
    <link:calculationArc order="13" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_444b1ac7-f47a-4ce3-0caa-537f7e4ab8c3" xlink:to="loc_us-gaap_IncreaseDecreaseInAccountsPayableTrade_ed38aedf-17a0-9062-826e-1ea210c311c0" xlink:type="arc" />
    <link:loc xlink:href="mg-20180930.xsd#mg_IncreaseDecreaseInOtherAccruedLiabilitiesAndDeferredLiabilities" xlink:label="loc_mg_IncreaseDecreaseInOtherAccruedLiabilitiesAndDeferredLiabilities_3e81cc3a-0b4a-bc4f-eaf0-7e1eb614b9b2" xlink:type="locator" />
    <link:calculationArc order="14" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_444b1ac7-f47a-4ce3-0caa-537f7e4ab8c3" xlink:to="loc_mg_IncreaseDecreaseInOtherAccruedLiabilitiesAndDeferredLiabilities_3e81cc3a-0b4a-bc4f-eaf0-7e1eb614b9b2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncreaseDecreaseInAccruedIncomeTaxesPayable" xlink:label="loc_us-gaap_IncreaseDecreaseInAccruedIncomeTaxesPayable_2e0100a2-70c7-ab53-9143-6f416ad2f702" xlink:type="locator" />
    <link:calculationArc order="15" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_444b1ac7-f47a-4ce3-0caa-537f7e4ab8c3" xlink:to="loc_us-gaap_IncreaseDecreaseInAccruedIncomeTaxesPayable_2e0100a2-70c7-ab53-9143-6f416ad2f702" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_70319186-e7bd-7189-88d2-eba26fb93350" xlink:type="locator" />
    <link:calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInContinuingOperations_4adbde80-36e3-b879-a631-f0caa0dbbe76" xlink:to="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_70319186-e7bd-7189-88d2-eba26fb93350" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:label="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_fee12b15-6b42-6245-2e2f-ff030b98332c" xlink:type="locator" />
    <link:calculationArc order="1" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_70319186-e7bd-7189-88d2-eba26fb93350" xlink:to="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_fee12b15-6b42-6245-2e2f-ff030b98332c" xlink:type="arc" />
    <link:loc xlink:href="mg-20180930.xsd#mg_PaymentsToAcquireIntangibleAssetsAndSoftware" xlink:label="loc_mg_PaymentsToAcquireIntangibleAssetsAndSoftware_dc39a5c4-314b-8f74-efdd-7e1eb5d5b193" xlink:type="locator" />
    <link:calculationArc order="2" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_70319186-e7bd-7189-88d2-eba26fb93350" xlink:to="loc_mg_PaymentsToAcquireIntangibleAssetsAndSoftware_dc39a5c4-314b-8f74-efdd-7e1eb5d5b193" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired" xlink:label="loc_us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired_9d35c912-5b2d-89f7-eeb3-812a0511db5e" xlink:type="locator" />
    <link:calculationArc order="3" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_70319186-e7bd-7189-88d2-eba26fb93350" xlink:to="loc_us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired_9d35c912-5b2d-89f7-eeb3-812a0511db5e" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ProceedsFromDivestitureOfBusinessesNetOfCashDivested" xlink:label="loc_us-gaap_ProceedsFromDivestitureOfBusinessesNetOfCashDivested_dab9eb40-75c0-0031-04d2-65a045b74473" xlink:type="locator" />
    <link:calculationArc order="4" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_70319186-e7bd-7189-88d2-eba26fb93350" xlink:to="loc_us-gaap_ProceedsFromDivestitureOfBusinessesNetOfCashDivested_dab9eb40-75c0-0031-04d2-65a045b74473" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment" xlink:label="loc_us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment_f7ed6106-862d-edb5-3fd1-677e7651af64" xlink:type="locator" />
    <link:calculationArc order="5" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_70319186-e7bd-7189-88d2-eba26fb93350" xlink:to="loc_us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment_f7ed6106-862d-edb5-3fd1-677e7651af64" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_deb49b68-c030-7624-a39d-ea301caa5dbf" xlink:type="locator" />
    <link:calculationArc order="3" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInContinuingOperations_4adbde80-36e3-b879-a631-f0caa0dbbe76" xlink:to="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_deb49b68-c030-7624-a39d-ea301caa5dbf" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RepaymentsOfLongTermCapitalLeaseObligations" xlink:label="loc_us-gaap_RepaymentsOfLongTermCapitalLeaseObligations_8f563464-80d3-5024-06bd-d0b7c03ce96e" xlink:type="locator" />
    <link:calculationArc order="1" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_deb49b68-c030-7624-a39d-ea301caa5dbf" xlink:to="loc_us-gaap_RepaymentsOfLongTermCapitalLeaseObligations_8f563464-80d3-5024-06bd-d0b7c03ce96e" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ProceedsFromIssuanceOfLongTermDebt" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfLongTermDebt_e5f1c7a4-b42a-8461-2001-b1f20e51b257" xlink:type="locator" />
    <link:calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_deb49b68-c030-7624-a39d-ea301caa5dbf" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfLongTermDebt_e5f1c7a4-b42a-8461-2001-b1f20e51b257" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RepaymentsOfLongTermDebt" xlink:label="loc_us-gaap_RepaymentsOfLongTermDebt_2b72fe5f-3c0e-d5e0-8e5c-ad01818e58e5" xlink:type="locator" />
    <link:calculationArc order="3" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_deb49b68-c030-7624-a39d-ea301caa5dbf" xlink:to="loc_us-gaap_RepaymentsOfLongTermDebt_2b72fe5f-3c0e-d5e0-8e5c-ad01818e58e5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ProceedsFromLinesOfCredit" xlink:label="loc_us-gaap_ProceedsFromLinesOfCredit_bce346aa-ba15-aeef-61ad-e8ce13a3f0b4" xlink:type="locator" />
    <link:calculationArc order="4" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_deb49b68-c030-7624-a39d-ea301caa5dbf" xlink:to="loc_us-gaap_ProceedsFromLinesOfCredit_bce346aa-ba15-aeef-61ad-e8ce13a3f0b4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RepaymentsOfLinesOfCredit" xlink:label="loc_us-gaap_RepaymentsOfLinesOfCredit_0e65f67a-86e3-c84f-fab4-e2c0fc4b175d" xlink:type="locator" />
    <link:calculationArc order="5" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_deb49b68-c030-7624-a39d-ea301caa5dbf" xlink:to="loc_us-gaap_RepaymentsOfLinesOfCredit_0e65f67a-86e3-c84f-fab4-e2c0fc4b175d" xlink:type="arc" />
    <link:loc xlink:href="mg-20180930.xsd#mg_PaymentsOfContingentConsiderationForBusinessAcquisitions" xlink:label="loc_mg_PaymentsOfContingentConsiderationForBusinessAcquisitions_d956e3e1-86ff-cb29-2748-7e1eb5f443a4" xlink:type="locator" />
    <link:calculationArc order="6" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_deb49b68-c030-7624-a39d-ea301caa5dbf" xlink:to="loc_mg_PaymentsOfContingentConsiderationForBusinessAcquisitions_d956e3e1-86ff-cb29-2748-7e1eb5f443a4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PaymentsForRepurchaseOfCommonStock" xlink:label="loc_us-gaap_PaymentsForRepurchaseOfCommonStock_8a1490c4-32d9-5132-1fe2-2675a45abdae" xlink:type="locator" />
    <link:calculationArc order="7" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_deb49b68-c030-7624-a39d-ea301caa5dbf" xlink:to="loc_us-gaap_PaymentsForRepurchaseOfCommonStock_8a1490c4-32d9-5132-1fe2-2675a45abdae" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation" xlink:label="loc_us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation_6d67f644-e190-e5ce-9449-e00a27ad7771" xlink:type="locator" />
    <link:calculationArc order="8" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_deb49b68-c030-7624-a39d-ea301caa5dbf" xlink:to="loc_us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation_6d67f644-e190-e5ce-9449-e00a27ad7771" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ProceedsFromStockOptionsExercised" xlink:label="loc_us-gaap_ProceedsFromStockOptionsExercised_d04df344-47da-0222-79d0-99b7d739fd60" xlink:type="locator" />
    <link:calculationArc order="9" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_deb49b68-c030-7624-a39d-ea301caa5dbf" xlink:to="loc_us-gaap_ProceedsFromStockOptionsExercised_d04df344-47da-0222-79d0-99b7d739fd60" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EffectOfExchangeRateOnCashAndCashEquivalentsContinuingOperations" xlink:label="loc_us-gaap_EffectOfExchangeRateOnCashAndCashEquivalentsContinuingOperations_4a87d5fb-7685-5e76-b0e2-ed69b64d53fb" xlink:type="locator" />
    <link:calculationArc order="4" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInContinuingOperations_4adbde80-36e3-b879-a631-f0caa0dbbe76" xlink:to="loc_us-gaap_EffectOfExchangeRateOnCashAndCashEquivalentsContinuingOperations_4a87d5fb-7685-5e76-b0e2-ed69b64d53fb" xlink:type="arc" />
  </link:calculationLink>
  <link:calculationLink xlink:role="http://www.mistrasgroup.com/role/UnauditedCondensedConsolidatedStatementsOfComprehensiveIncomeLoss" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ComprehensiveIncomeNetOfTax" xlink:label="loc_us-gaap_ComprehensiveIncomeNetOfTax_499015ce-2160-aed2-85a3-080e8c4c6cdf" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest" xlink:label="loc_us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest_dd69e307-3cf6-284a-5315-8fa7ac464283" xlink:type="locator" />
    <link:calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTax_499015ce-2160-aed2-85a3-080e8c4c6cdf" xlink:to="loc_us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest_dd69e307-3cf6-284a-5315-8fa7ac464283" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ProfitLoss" xlink:label="loc_us-gaap_ProfitLoss_adacf05e-7e15-bd60-3e53-87432885dc29" xlink:type="locator" />
    <link:calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest_dd69e307-3cf6-284a-5315-8fa7ac464283" xlink:to="loc_us-gaap_ProfitLoss_adacf05e-7e15-bd60-3e53-87432885dc29" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax_351eeed0-a987-88e4-c007-095f3644ffff" xlink:type="locator" />
    <link:calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest_dd69e307-3cf6-284a-5315-8fa7ac464283" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax_351eeed0-a987-88e4-c007-095f3644ffff" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest" xlink:label="loc_us-gaap_ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest_7908f590-67cb-1122-d422-880e24cad7ce" xlink:type="locator" />
    <link:calculationArc order="2" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTax_499015ce-2160-aed2-85a3-080e8c4c6cdf" xlink:to="loc_us-gaap_ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest_7908f590-67cb-1122-d422-880e24cad7ce" xlink:type="arc" />
  </link:calculationLink>
  <link:calculationLink xlink:role="http://www.mistrasgroup.com/role/UnauditedCondensedConsolidatedStatementsOfIncomeLoss" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NetIncomeLoss" xlink:label="loc_us-gaap_NetIncomeLoss_641b1cab-a2b3-2e0e-8389-1455ff3f8581" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ProfitLoss" xlink:label="loc_us-gaap_ProfitLoss_adacf05e-7e15-bd60-3e53-87432885dc29" xlink:type="locator" />
    <link:calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetIncomeLoss_641b1cab-a2b3-2e0e-8389-1455ff3f8581" xlink:to="loc_us-gaap_ProfitLoss_adacf05e-7e15-bd60-3e53-87432885dc29" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments_0eb47183-f513-314d-ceda-ee2412d9eee8" xlink:type="locator" />
    <link:calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_ProfitLoss_adacf05e-7e15-bd60-3e53-87432885dc29" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments_0eb47183-f513-314d-ceda-ee2412d9eee8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OperatingIncomeLoss" xlink:label="loc_us-gaap_OperatingIncomeLoss_9894e895-7695-402a-9f03-08d60b7373b8" xlink:type="locator" />
    <link:calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments_0eb47183-f513-314d-ceda-ee2412d9eee8" xlink:to="loc_us-gaap_OperatingIncomeLoss_9894e895-7695-402a-9f03-08d60b7373b8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_GrossProfit" xlink:label="loc_us-gaap_GrossProfit_aaae347c-fa91-e2c3-dd05-1b008b13fd0c" xlink:type="locator" />
    <link:calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingIncomeLoss_9894e895-7695-402a-9f03-08d60b7373b8" xlink:to="loc_us-gaap_GrossProfit_aaae347c-fa91-e2c3-dd05-1b008b13fd0c" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_f8614c43-5d24-68f7-ca63-14ebca646494" xlink:type="locator" />
    <link:calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_GrossProfit_aaae347c-fa91-e2c3-dd05-1b008b13fd0c" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_f8614c43-5d24-68f7-ca63-14ebca646494" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CostOfGoodsSoldExcludingDepreciationDepletionAndAmortization" xlink:label="loc_us-gaap_CostOfGoodsSoldExcludingDepreciationDepletionAndAmortization_097bb389-ffb1-7c26-263e-0335c26bc95a" xlink:type="locator" />
    <link:calculationArc order="2" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_GrossProfit_aaae347c-fa91-e2c3-dd05-1b008b13fd0c" xlink:to="loc_us-gaap_CostOfGoodsSoldExcludingDepreciationDepletionAndAmortization_097bb389-ffb1-7c26-263e-0335c26bc95a" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CostOfGoodsAndServicesSoldDepreciation" xlink:label="loc_us-gaap_CostOfGoodsAndServicesSoldDepreciation_84509451-1f60-36a6-d64c-7c15207efbd6" xlink:type="locator" />
    <link:calculationArc order="3" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_GrossProfit_aaae347c-fa91-e2c3-dd05-1b008b13fd0c" xlink:to="loc_us-gaap_CostOfGoodsAndServicesSoldDepreciation_84509451-1f60-36a6-d64c-7c15207efbd6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SellingGeneralAndAdministrativeExpense" xlink:label="loc_us-gaap_SellingGeneralAndAdministrativeExpense_29ad42f4-24c5-90ea-4492-fdb757d66249" xlink:type="locator" />
    <link:calculationArc order="2" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingIncomeLoss_9894e895-7695-402a-9f03-08d60b7373b8" xlink:to="loc_us-gaap_SellingGeneralAndAdministrativeExpense_29ad42f4-24c5-90ea-4492-fdb757d66249" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_GoodwillAndIntangibleAssetImpairment" xlink:label="loc_us-gaap_GoodwillAndIntangibleAssetImpairment_46ff7060-620f-71f6-4d86-16b841ded8cf" xlink:type="locator" />
    <link:calculationArc order="3" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingIncomeLoss_9894e895-7695-402a-9f03-08d60b7373b8" xlink:to="loc_us-gaap_GoodwillAndIntangibleAssetImpairment_46ff7060-620f-71f6-4d86-16b841ded8cf" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LossContingencyAccrualProvision" xlink:label="loc_us-gaap_LossContingencyAccrualProvision_8edecb72-1896-c0f4-96c1-af9d830b8944" xlink:type="locator" />
    <link:calculationArc order="4" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingIncomeLoss_9894e895-7695-402a-9f03-08d60b7373b8" xlink:to="loc_us-gaap_LossContingencyAccrualProvision_8edecb72-1896-c0f4-96c1-af9d830b8944" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DisposalGroupNotDiscontinuedOperationGainLossOnDisposal" xlink:label="loc_us-gaap_DisposalGroupNotDiscontinuedOperationGainLossOnDisposal_03e83c30-c623-f96c-29f8-521a710884ee" xlink:type="locator" />
    <link:calculationArc order="5" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingIncomeLoss_9894e895-7695-402a-9f03-08d60b7373b8" xlink:to="loc_us-gaap_DisposalGroupNotDiscontinuedOperationGainLossOnDisposal_03e83c30-c623-f96c-29f8-521a710884ee" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ResearchAndDevelopmentExpense" xlink:label="loc_us-gaap_ResearchAndDevelopmentExpense_25ae5ce2-b413-b975-9a84-c7503d2496cf" xlink:type="locator" />
    <link:calculationArc order="6" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingIncomeLoss_9894e895-7695-402a-9f03-08d60b7373b8" xlink:to="loc_us-gaap_ResearchAndDevelopmentExpense_25ae5ce2-b413-b975-9a84-c7503d2496cf" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DepreciationAndAmortization" xlink:label="loc_us-gaap_DepreciationAndAmortization_cfab4180-0727-b022-76c1-dcd34f4a6382" xlink:type="locator" />
    <link:calculationArc order="7" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingIncomeLoss_9894e895-7695-402a-9f03-08d60b7373b8" xlink:to="loc_us-gaap_DepreciationAndAmortization_cfab4180-0727-b022-76c1-dcd34f4a6382" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LitigationSettlementExpense" xlink:label="loc_us-gaap_LitigationSettlementExpense_58ce9b83-14ec-becd-d9b4-8d51ba4f6656" xlink:type="locator" />
    <link:calculationArc order="8" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingIncomeLoss_9894e895-7695-402a-9f03-08d60b7373b8" xlink:to="loc_us-gaap_LitigationSettlementExpense_58ce9b83-14ec-becd-d9b4-8d51ba4f6656" xlink:type="arc" />
    <link:loc xlink:href="mg-20180930.xsd#mg_AcquisitionRelatedCostsAndFairValueAdjustmentsToInitialPurchasePriceAllocation" xlink:label="loc_mg_AcquisitionRelatedCostsAndFairValueAdjustmentsToInitialPurchasePriceAllocation_8fddf963-27d7-b6c0-d30a-7e1eb6231df0" xlink:type="locator" />
    <link:calculationArc order="9" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingIncomeLoss_9894e895-7695-402a-9f03-08d60b7373b8" xlink:to="loc_mg_AcquisitionRelatedCostsAndFairValueAdjustmentsToInitialPurchasePriceAllocation_8fddf963-27d7-b6c0-d30a-7e1eb6231df0" xlink:type="arc" />
    <link:loc xlink:href="mg-20180930.xsd#mg_InterestExpenseAndAmortizationOfDeferredCharges" xlink:label="loc_mg_InterestExpenseAndAmortizationOfDeferredCharges_f4c95afe-3f37-8e49-78ab-7e1eb5e573f2" xlink:type="locator" />
    <link:calculationArc order="2" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments_0eb47183-f513-314d-ceda-ee2412d9eee8" xlink:to="loc_mg_InterestExpenseAndAmortizationOfDeferredCharges_f4c95afe-3f37-8e49-78ab-7e1eb5e573f2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncomeTaxExpenseBenefit" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_78b7d85e-8366-fe6d-cb1f-faac5a041b79" xlink:type="locator" />
    <link:calculationArc order="2" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_ProfitLoss_adacf05e-7e15-bd60-3e53-87432885dc29" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_78b7d85e-8366-fe6d-cb1f-faac5a041b79" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NetIncomeLossAttributableToNoncontrollingInterest" xlink:label="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_baabbf0a-644b-708a-c310-1211f9af2775" xlink:type="locator" />
    <link:calculationArc order="2" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetIncomeLoss_641b1cab-a2b3-2e0e-8389-1455ff3f8581" xlink:to="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_baabbf0a-644b-708a-c310-1211f9af2775" xlink:type="arc" />
  </link:calculationLink>
</link:linkbase>
