<?xml version="1.0" encoding="UTF-8"?>

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2026 Workiva-->
<!--r:01a0205d-ef1f-716b-a0db-10dd58284085,g:af487b98-d6a4-4fdb-9e73-df22b5a81566-->
<link:linkbase 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" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <link:arcroleRef arcroleURI="https://xbrl.org/2023/arcrole/summation-item" xlink:type="simple" xlink:href="https://www.xbrl.org/2023/calculation-1.1.xsd#summation-item"/>
  <link:roleRef roleURI="http://www.protolabs.com/role/ConsolidatedBalanceSheets" xlink:type="simple" xlink:href="prlb-20260930.xsd#ConsolidatedBalanceSheets"/>
  <link:calculationLink xlink:role="http://www.protolabs.com/role/ConsolidatedBalanceSheets" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets_01a0205d-efbb-7bf3-aef7-dd2053ea9471" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Assets"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsCurrent_01a0205d-efbb-753e-87b7-e08f6e724741" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetsCurrent"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_01a0205d-efbb-7bf3-aef7-dd2053ea9471" xlink:to="loc_us-gaap_AssetsCurrent_01a0205d-efbb-753e-87b7-e08f6e724741" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_01a0205d-efbb-76d0-b53f-c56102817d0f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PropertyPlantAndEquipmentNet"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_01a0205d-efbb-7bf3-aef7-dd2053ea9471" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_01a0205d-efbb-76d0-b53f-c56102817d0f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_01a0205d-efbb-731c-843e-ad43723e94ce" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Goodwill"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_01a0205d-efbb-7bf3-aef7-dd2053ea9471" xlink:to="loc_us-gaap_Goodwill_01a0205d-efbb-731c-843e-ad43723e94ce" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherIntangibleAssetsNet_01a0205d-efbb-7d19-a3fe-bdb036b7fa45" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherIntangibleAssetsNet"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_01a0205d-efbb-7bf3-aef7-dd2053ea9471" xlink:to="loc_us-gaap_OtherIntangibleAssetsNet_01a0205d-efbb-7d19-a3fe-bdb036b7fa45" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MarketableSecuritiesNoncurrent_01a0205d-efbb-7d0c-a0a3-7e68e0d330e2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MarketableSecuritiesNoncurrent"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_01a0205d-efbb-7bf3-aef7-dd2053ea9471" xlink:to="loc_us-gaap_MarketableSecuritiesNoncurrent_01a0205d-efbb-7d0c-a0a3-7e68e0d330e2" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseRightOfUseAsset_01a0205d-efbb-777f-b52b-7f4a4ff9cda3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingLeaseRightOfUseAsset"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_01a0205d-efbb-7bf3-aef7-dd2053ea9471" xlink:to="loc_us-gaap_OperatingLeaseRightOfUseAsset_01a0205d-efbb-777f-b52b-7f4a4ff9cda3" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseRightOfUseAsset_01a0205d-efbb-7860-be5e-63dcafa0d791" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinanceLeaseRightOfUseAsset"/>
    <link:calculationArc order="7" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_01a0205d-efbb-7bf3-aef7-dd2053ea9471" xlink:to="loc_us-gaap_FinanceLeaseRightOfUseAsset_01a0205d-efbb-7860-be5e-63dcafa0d791" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssetsNoncurrent_01a0205d-efbb-7d2d-8c5d-8ee05905a2b5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherAssetsNoncurrent"/>
    <link:calculationArc order="8" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_01a0205d-efbb-7bf3-aef7-dd2053ea9471" xlink:to="loc_us-gaap_OtherAssetsNoncurrent_01a0205d-efbb-7d2d-8c5d-8ee05905a2b5" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_01a0205d-efbb-7d0f-8081-2a98bd0420f2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquity"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockValue_01a0205d-efbb-7a3f-b4fa-d69b4b1789fe" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockValue"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_01a0205d-efbb-7d0f-8081-2a98bd0420f2" xlink:to="loc_us-gaap_PreferredStockValue_01a0205d-efbb-7a3f-b4fa-d69b4b1789fe" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockValue_01a0205d-efbb-7266-bc25-c0a86b7ceaac" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockValue"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_01a0205d-efbb-7d0f-8081-2a98bd0420f2" xlink:to="loc_us-gaap_CommonStockValue_01a0205d-efbb-7266-bc25-c0a86b7ceaac" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalCommonStock_01a0205d-efbb-7050-9016-69320364ba3c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AdditionalPaidInCapitalCommonStock"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_01a0205d-efbb-7d0f-8081-2a98bd0420f2" xlink:to="loc_us-gaap_AdditionalPaidInCapitalCommonStock_01a0205d-efbb-7050-9016-69320364ba3c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsAccumulatedDeficit_01a0205d-efbb-76df-8b9b-0f14f72dbcd5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RetainedEarningsAccumulatedDeficit"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_01a0205d-efbb-7d0f-8081-2a98bd0420f2" xlink:to="loc_us-gaap_RetainedEarningsAccumulatedDeficit_01a0205d-efbb-76df-8b9b-0f14f72dbcd5" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_01a0205d-efbb-763b-b2da-30914e71d619" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_01a0205d-efbb-7d0f-8081-2a98bd0420f2" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_01a0205d-efbb-763b-b2da-30914e71d619" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsCurrent_01a0205d-efbb-7517-98d5-6ed79b2f07aa" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetsCurrent"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_01a0205d-efbb-771e-99c5-e04b5b36d60b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsCurrent_01a0205d-efbb-7517-98d5-6ed79b2f07aa" xlink:to="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_01a0205d-efbb-771e-99c5-e04b5b36d60b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MarketableSecuritiesCurrent_01a0205d-efbb-713b-954f-57b31493e18f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MarketableSecuritiesCurrent"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsCurrent_01a0205d-efbb-7517-98d5-6ed79b2f07aa" xlink:to="loc_us-gaap_MarketableSecuritiesCurrent_01a0205d-efbb-713b-954f-57b31493e18f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsReceivableNetCurrent_01a0205d-efbb-7f12-a8d8-33ff83620853" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccountsReceivableNetCurrent"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsCurrent_01a0205d-efbb-7517-98d5-6ed79b2f07aa" xlink:to="loc_us-gaap_AccountsReceivableNetCurrent_01a0205d-efbb-7f12-a8d8-33ff83620853" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryNet_01a0205d-efbb-7b23-8612-db61550497e7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InventoryNet"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsCurrent_01a0205d-efbb-7517-98d5-6ed79b2f07aa" xlink:to="loc_us-gaap_InventoryNet_01a0205d-efbb-7b23-8612-db61550497e7" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PrepaidExpenseAndOtherAssetsCurrent_01a0205d-efbb-7ba8-9e51-21cdf0dfc868" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PrepaidExpenseAndOtherAssetsCurrent"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsCurrent_01a0205d-efbb-7517-98d5-6ed79b2f07aa" xlink:to="loc_us-gaap_PrepaidExpenseAndOtherAssetsCurrent_01a0205d-efbb-7ba8-9e51-21cdf0dfc868" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxesReceivable_01a0205d-efbb-7d18-966e-6837a6f7d183" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeTaxesReceivable"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsCurrent_01a0205d-efbb-7517-98d5-6ed79b2f07aa" xlink:to="loc_us-gaap_IncomeTaxesReceivable_01a0205d-efbb-7d18-966e-6837a6f7d183" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquity_01a0205d-efbb-778c-b7c8-ad49556c4222" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilitiesAndStockholdersEquity"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Liabilities_01a0205d-efbb-7326-bcad-3565c4b5bee3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Liabilities"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquity_01a0205d-efbb-778c-b7c8-ad49556c4222" xlink:to="loc_us-gaap_Liabilities_01a0205d-efbb-7326-bcad-3565c4b5bee3" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_01a0205d-efbb-7f46-8b15-dbde4df16d5b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquity"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquity_01a0205d-efbb-778c-b7c8-ad49556c4222" xlink:to="loc_us-gaap_StockholdersEquity_01a0205d-efbb-7f46-8b15-dbde4df16d5b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesCurrent_01a0205d-efbb-7b2c-9b61-957e65b39062" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilitiesCurrent"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsPayableCurrent_01a0205d-efbb-76d7-ad50-5dcf3288c65f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccountsPayableCurrent"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesCurrent_01a0205d-efbb-7b2c-9b61-957e65b39062" xlink:to="loc_us-gaap_AccountsPayableCurrent_01a0205d-efbb-76d7-ad50-5dcf3288c65f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeRelatedLiabilitiesCurrent_01a0205d-efbb-7004-96b2-64b97e730d6a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EmployeeRelatedLiabilitiesCurrent"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesCurrent_01a0205d-efbb-7b2c-9b61-957e65b39062" xlink:to="loc_us-gaap_EmployeeRelatedLiabilitiesCurrent_01a0205d-efbb-7004-96b2-64b97e730d6a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccruedLiabilitiesAndOtherLiabilities_01a0205d-efbb-70f1-bfb6-9cd9822e4111" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccruedLiabilitiesAndOtherLiabilities"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesCurrent_01a0205d-efbb-7b2c-9b61-957e65b39062" xlink:to="loc_us-gaap_AccruedLiabilitiesAndOtherLiabilities_01a0205d-efbb-70f1-bfb6-9cd9822e4111" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiabilityCurrent_01a0205d-efbb-78da-b785-ddd13c2abfdd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingLeaseLiabilityCurrent"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesCurrent_01a0205d-efbb-7b2c-9b61-957e65b39062" xlink:to="loc_us-gaap_OperatingLeaseLiabilityCurrent_01a0205d-efbb-78da-b785-ddd13c2abfdd" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiabilityCurrent_01a0205d-efbb-7759-b281-82ae7ca91235" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinanceLeaseLiabilityCurrent"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesCurrent_01a0205d-efbb-7b2c-9b61-957e65b39062" xlink:to="loc_us-gaap_FinanceLeaseLiabilityCurrent_01a0205d-efbb-7759-b281-82ae7ca91235" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Liabilities_01a0205d-efbb-750f-992a-b01a6b0c7f08" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Liabilities"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesCurrent_01a0205d-efbb-7291-b487-079615830194" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilitiesCurrent"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_01a0205d-efbb-750f-992a-b01a6b0c7f08" xlink:to="loc_us-gaap_LiabilitiesCurrent_01a0205d-efbb-7291-b487-079615830194" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiabilityNoncurrent_01a0205d-efbb-7b8a-8f6a-0f58d58c476a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingLeaseLiabilityNoncurrent"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_01a0205d-efbb-750f-992a-b01a6b0c7f08" xlink:to="loc_us-gaap_OperatingLeaseLiabilityNoncurrent_01a0205d-efbb-7b8a-8f6a-0f58d58c476a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredIncomeTaxLiabilitiesNet_01a0205d-efbb-7199-84d5-72a306e7bb57" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DeferredIncomeTaxLiabilitiesNet"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_01a0205d-efbb-750f-992a-b01a6b0c7f08" xlink:to="loc_us-gaap_DeferredIncomeTaxLiabilitiesNet_01a0205d-efbb-7199-84d5-72a306e7bb57" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherLiabilitiesNoncurrent_01a0205d-efbb-766e-8fd2-aebab39ae35d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherLiabilitiesNoncurrent"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_01a0205d-efbb-750f-992a-b01a6b0c7f08" xlink:to="loc_us-gaap_OtherLiabilitiesNoncurrent_01a0205d-efbb-766e-8fd2-aebab39ae35d" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.protolabs.com/role/ConsolidatedStatementsofComprehensiveIncome" xlink:type="simple" xlink:href="prlb-20260930.xsd#ConsolidatedStatementsofComprehensiveIncome"/>
  <link:calculationLink xlink:role="http://www.protolabs.com/role/ConsolidatedStatementsofComprehensiveIncome" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingExpenses_01a0205d-efbb-74ec-8c17-a4d1dcb0bb84" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingExpenses"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SellingAndMarketingExpense_01a0205d-efbb-7a43-bc0e-a34d395d8338" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SellingAndMarketingExpense"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingExpenses_01a0205d-efbb-74ec-8c17-a4d1dcb0bb84" xlink:to="loc_us-gaap_SellingAndMarketingExpense_01a0205d-efbb-7a43-bc0e-a34d395d8338" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResearchAndDevelopmentExpense_01a0205d-efbb-775d-a7df-c49228374c28" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ResearchAndDevelopmentExpense"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingExpenses_01a0205d-efbb-74ec-8c17-a4d1dcb0bb84" xlink:to="loc_us-gaap_ResearchAndDevelopmentExpense_01a0205d-efbb-775d-a7df-c49228374c28" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeneralAndAdministrativeExpense_01a0205d-efbb-7749-a4f6-615d85d90b92" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GeneralAndAdministrativeExpense"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingExpenses_01a0205d-efbb-74ec-8c17-a4d1dcb0bb84" xlink:to="loc_us-gaap_GeneralAndAdministrativeExpense_01a0205d-efbb-7749-a4f6-615d85d90b92" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringCharges_01a0205d-efbb-733d-97e4-5af1f9e1f36f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestructuringCharges"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingExpenses_01a0205d-efbb-74ec-8c17-a4d1dcb0bb84" xlink:to="loc_us-gaap_RestructuringCharges_01a0205d-efbb-733d-97e4-5af1f9e1f36f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainLossOnSaleOfBusiness_01a0205d-efbb-794a-8447-7955d5b8b821" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GainLossOnSaleOfBusiness"/>
    <link:calculationArc order="5" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingExpenses_01a0205d-efbb-74ec-8c17-a4d1dcb0bb84" xlink:to="loc_us-gaap_GainLossOnSaleOfBusiness_01a0205d-efbb-794a-8447-7955d5b8b821" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GrossProfit_01a0205d-efbb-729c-aa49-dfd46fcc0b6f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GrossProfit"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax_01a0205d-efbb-7f22-bf75-87d061baff37" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_GrossProfit_01a0205d-efbb-729c-aa49-dfd46fcc0b6f" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax_01a0205d-efbb-7f22-bf75-87d061baff37" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfGoodsAndServicesSold_01a0205d-efbb-70a6-8cec-0e7df2d24ab5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CostOfGoodsAndServicesSold"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_GrossProfit_01a0205d-efbb-729c-aa49-dfd46fcc0b6f" xlink:to="loc_us-gaap_CostOfGoodsAndServicesSold_01a0205d-efbb-70a6-8cec-0e7df2d24ab5" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss_01a0205d-efbb-7ab2-a04d-77546d0cfb44" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingIncomeLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingExpenses_01a0205d-efbb-76ca-8844-21cb12e140ba" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingExpenses"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingIncomeLoss_01a0205d-efbb-7ab2-a04d-77546d0cfb44" xlink:to="loc_us-gaap_OperatingExpenses_01a0205d-efbb-76ca-8844-21cb12e140ba" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GrossProfit_01a0205d-efbb-7ff8-8b4e-1697ff69ae9f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GrossProfit"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingIncomeLoss_01a0205d-efbb-7ab2-a04d-77546d0cfb44" xlink:to="loc_us-gaap_GrossProfit_01a0205d-efbb-7ff8-8b4e-1697ff69ae9f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_01a0205d-efbb-7259-a236-543f604ebcb9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_01a0205d-efbb-7ba5-8c8e-4547e3058d7d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeTaxExpenseBenefit"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetIncomeLoss_01a0205d-efbb-7259-a236-543f604ebcb9" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_01a0205d-efbb-7ba5-8c8e-4547e3058d7d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_01a0205d-efbb-761a-b02e-b77226eb6b65" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetIncomeLoss_01a0205d-efbb-7259-a236-543f604ebcb9" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_01a0205d-efbb-761a-b02e-b77226eb6b65" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_01a0205d-efbb-7634-be54-4fe2e83f24a6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNonoperatingIncomeExpense_01a0205d-efbb-7ba6-acdb-3d2b75a1e884" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherNonoperatingIncomeExpense"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_01a0205d-efbb-7634-be54-4fe2e83f24a6" xlink:to="loc_us-gaap_OtherNonoperatingIncomeExpense_01a0205d-efbb-7ba6-acdb-3d2b75a1e884" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss_01a0205d-efbb-7b03-ac19-2aa516d03e67" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingIncomeLoss"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_01a0205d-efbb-7634-be54-4fe2e83f24a6" xlink:to="loc_us-gaap_OperatingIncomeLoss_01a0205d-efbb-7b03-ac19-2aa516d03e67" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.protolabs.com/role/ConsolidatedStatementsofCashFlows" xlink:type="simple" xlink:href="prlb-20260930.xsd#ConsolidatedStatementsofCashFlows"/>
  <link:calculationLink xlink:role="http://www.protolabs.com/role/ConsolidatedStatementsofCashFlows" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_01a0205d-efbb-778f-ae5e-633b4a32148d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsForRepurchaseOfCommonStock_01a0205d-efbb-7d5a-b919-115f2aaaefb1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsForRepurchaseOfCommonStock"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_01a0205d-efbb-778f-ae5e-633b4a32148d" xlink:to="loc_us-gaap_PaymentsForRepurchaseOfCommonStock_01a0205d-efbb-7d5a-b919-115f2aaaefb1" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation_01a0205d-efbb-7e81-88df-52f736e402f3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_01a0205d-efbb-778f-ae5e-633b4a32148d" xlink:to="loc_us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation_01a0205d-efbb-7e81-88df-52f736e402f3" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeasePrincipalPayments_01a0205d-efbb-7231-9c2b-aaa94e88fb1a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinanceLeasePrincipalPayments"/>
    <link:calculationArc order="3" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_01a0205d-efbb-778f-ae5e-633b4a32148d" xlink:to="loc_us-gaap_FinanceLeasePrincipalPayments_01a0205d-efbb-7231-9c2b-aaa94e88fb1a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlansIncludingStockOptions_01a0205d-efbb-77a7-8262-8d3975e78d7d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlansIncludingStockOptions"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_01a0205d-efbb-778f-ae5e-633b4a32148d" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlansIncludingStockOptions_01a0205d-efbb-77a7-8262-8d3975e78d7d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_01a0205d-efbb-730a-af8e-a844ce20b8a6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromSaleOfProductiveAssets_01a0205d-efbb-7ba4-a753-0929759ee53c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromSaleOfProductiveAssets"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_01a0205d-efbb-730a-af8e-a844ce20b8a6" xlink:to="loc_us-gaap_ProceedsFromSaleOfProductiveAssets_01a0205d-efbb-7ba4-a753-0929759ee53c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_01a0205d-efbb-78ae-81cd-4bef089471aa" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsToAcquirePropertyPlantAndEquipment"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_01a0205d-efbb-730a-af8e-a844ce20b8a6" xlink:to="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_01a0205d-efbb-78ae-81cd-4bef089471aa" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireAvailableForSaleSecuritiesDebt_01a0205d-efbb-7275-a04e-74df6bf0c353" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsToAcquireAvailableForSaleSecuritiesDebt"/>
    <link:calculationArc order="3" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_01a0205d-efbb-730a-af8e-a844ce20b8a6" xlink:to="loc_us-gaap_PaymentsToAcquireAvailableForSaleSecuritiesDebt_01a0205d-efbb-7275-a04e-74df6bf0c353" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities_01a0205d-efbb-7416-8687-a0b7ff4c17c0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_01a0205d-efbb-730a-af8e-a844ce20b8a6" xlink:to="loc_us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities_01a0205d-efbb-7416-8687-a0b7ff4c17c0" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_01a0205d-efbb-7c65-8e16-3d3b13db243f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_01a0205d-efbb-7591-b2ef-1df11df97501" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLoss"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_01a0205d-efbb-7c65-8e16-3d3b13db243f" xlink:to="loc_us-gaap_NetIncomeLoss_01a0205d-efbb-7591-b2ef-1df11df97501" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepreciationDepletionAndAmortization_01a0205d-efbb-75f7-9aa2-23c92e378010" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DepreciationDepletionAndAmortization"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_01a0205d-efbb-7c65-8e16-3d3b13db243f" xlink:to="loc_us-gaap_DepreciationDepletionAndAmortization_01a0205d-efbb-75f7-9aa2-23c92e378010" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensation_01a0205d-efbb-7b95-b177-efcb1263760a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensation"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_01a0205d-efbb-7c65-8e16-3d3b13db243f" xlink:to="loc_us-gaap_ShareBasedCompensation_01a0205d-efbb-7b95-b177-efcb1263760a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredIncomeTaxExpenseBenefit_01a0205d-efbb-7168-946c-ff938c4f105d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DeferredIncomeTaxExpenseBenefit"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_01a0205d-efbb-7c65-8e16-3d3b13db243f" xlink:to="loc_us-gaap_DeferredIncomeTaxExpenseBenefit_01a0205d-efbb-7168-946c-ff938c4f105d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccretionExpense_01a0205d-efbb-7c01-ab9c-7c95b4011789" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccretionExpense"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_01a0205d-efbb-7c65-8e16-3d3b13db243f" xlink:to="loc_us-gaap_AccretionExpense_01a0205d-efbb-7c01-ab9c-7c95b4011789" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ImpairmentOfLongLivedAssetsToBeDisposedOf_01a0205d-efbb-7d5d-9b67-457b2da5e580" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ImpairmentOfLongLivedAssetsToBeDisposedOf"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_01a0205d-efbb-7c65-8e16-3d3b13db243f" xlink:to="loc_us-gaap_ImpairmentOfLongLivedAssetsToBeDisposedOf_01a0205d-efbb-7d5d-9b67-457b2da5e580" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupNotDiscontinuedOperationLossGainOnWriteDown_01a0205d-efbb-7919-a860-8cde8b26408b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisposalGroupNotDiscontinuedOperationLossGainOnWriteDown"/>
    <link:calculationArc order="7" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_01a0205d-efbb-7c65-8e16-3d3b13db243f" xlink:to="loc_us-gaap_DisposalGroupNotDiscontinuedOperationLossGainOnWriteDown_01a0205d-efbb-7919-a860-8cde8b26408b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainLossOnSaleOfPropertyPlantEquipment_01a0205d-efbb-7142-bc80-7e971a4837a0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GainLossOnSaleOfPropertyPlantEquipment"/>
    <link:calculationArc order="8" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_01a0205d-efbb-7c65-8e16-3d3b13db243f" xlink:to="loc_us-gaap_GainLossOnSaleOfPropertyPlantEquipment_01a0205d-efbb-7142-bc80-7e971a4837a0" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherOperatingActivitiesCashFlowStatement_01a0205d-efbb-7b15-b472-88e04965c323" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherOperatingActivitiesCashFlowStatement"/>
    <link:calculationArc order="9" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_01a0205d-efbb-7c65-8e16-3d3b13db243f" xlink:to="loc_us-gaap_OtherOperatingActivitiesCashFlowStatement_01a0205d-efbb-7b15-b472-88e04965c323" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInAccountsReceivable_01a0205d-efbb-7ff7-ba3e-61900cc4085f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInAccountsReceivable"/>
    <link:calculationArc order="10" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_01a0205d-efbb-7c65-8e16-3d3b13db243f" xlink:to="loc_us-gaap_IncreaseDecreaseInAccountsReceivable_01a0205d-efbb-7ff7-ba3e-61900cc4085f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInInventories_01a0205d-efbb-7ce1-b875-7d699f240561" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInInventories"/>
    <link:calculationArc order="11" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_01a0205d-efbb-7c65-8e16-3d3b13db243f" xlink:to="loc_us-gaap_IncreaseDecreaseInInventories_01a0205d-efbb-7ce1-b875-7d699f240561" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_01a0205d-efbb-76e7-a020-53274caa3de6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets"/>
    <link:calculationArc order="12" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_01a0205d-efbb-7c65-8e16-3d3b13db243f" xlink:to="loc_us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_01a0205d-efbb-76e7-a020-53274caa3de6" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInAccruedIncomeTaxesPayable_01a0205d-efbb-75f2-a052-2b6f4b873124" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInAccruedIncomeTaxesPayable"/>
    <link:calculationArc order="13" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_01a0205d-efbb-7c65-8e16-3d3b13db243f" xlink:to="loc_us-gaap_IncreaseDecreaseInAccruedIncomeTaxesPayable_01a0205d-efbb-75f2-a052-2b6f4b873124" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInAccountsPayable_01a0205d-efbb-791d-a055-6bb5f7f63447" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInAccountsPayable"/>
    <link:calculationArc order="14" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_01a0205d-efbb-7c65-8e16-3d3b13db243f" xlink:to="loc_us-gaap_IncreaseDecreaseInAccountsPayable_01a0205d-efbb-791d-a055-6bb5f7f63447" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInAccruedLiabilitiesAndOtherOperatingLiabilities_01a0205d-efbb-76ba-bbec-7935fc8a575b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInAccruedLiabilitiesAndOtherOperatingLiabilities"/>
    <link:calculationArc order="15" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_01a0205d-efbb-7c65-8e16-3d3b13db243f" xlink:to="loc_us-gaap_IncreaseDecreaseInAccruedLiabilitiesAndOtherOperatingLiabilities_01a0205d-efbb-76ba-bbec-7935fc8a575b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_01a0205d-efbb-7e8c-af22-70280d3fa096" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations_01a0205d-efbb-79fc-8299-3b9eb6c4c47f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_01a0205d-efbb-7e8c-af22-70280d3fa096" xlink:to="loc_us-gaap_EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations_01a0205d-efbb-79fc-8299-3b9eb6c4c47f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_01a0205d-efbb-7478-8223-9f4d09215258" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_01a0205d-efbb-7e8c-af22-70280d3fa096" xlink:to="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_01a0205d-efbb-7478-8223-9f4d09215258" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_01a0205d-efbb-7911-b086-c6cacbdbeef2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_01a0205d-efbb-7e8c-af22-70280d3fa096" xlink:to="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_01a0205d-efbb-7911-b086-c6cacbdbeef2" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_01a0205d-efbb-7e97-9cb2-c1451bbe8f34" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_01a0205d-efbb-7e8c-af22-70280d3fa096" xlink:to="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_01a0205d-efbb-7e97-9cb2-c1451bbe8f34" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.protolabs.com/role/NetIncomeperCommonShareScheduleofComputationOfBasicandDilutedNetIncomePerShareDetails" xlink:type="simple" xlink:href="prlb-20260930.xsd#NetIncomeperCommonShareScheduleofComputationOfBasicandDilutedNetIncomePerShareDetails"/>
  <link:calculationLink xlink:role="http://www.protolabs.com/role/NetIncomeperCommonShareScheduleofComputationOfBasicandDilutedNetIncomePerShareDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_01a0205d-efbb-7e76-a521-ed94b52e2921" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_01a0205d-efbb-742a-b5c6-3526e2736040" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_01a0205d-efbb-7e76-a521-ed94b52e2921" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_01a0205d-efbb-742a-b5c6-3526e2736040" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements_01a0205d-efbb-7355-9719-528e863e51ef" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_01a0205d-efbb-7e76-a521-ed94b52e2921" xlink:to="loc_us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements_01a0205d-efbb-7355-9719-528e863e51ef" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.protolabs.com/role/GoodwillandOtherIntangibleAssetsScheduleofIntangibleAssetsOtherThanGoodwillDetails" xlink:type="simple" xlink:href="prlb-20260930.xsd#GoodwillandOtherIntangibleAssetsScheduleofIntangibleAssetsOtherThanGoodwillDetails"/>
  <link:calculationLink xlink:role="http://www.protolabs.com/role/GoodwillandOtherIntangibleAssetsScheduleofIntangibleAssetsOtherThanGoodwillDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNet_01a0205d-efbb-7169-8401-5a495d3f6234" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsNet"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsGross_01a0205d-efbb-78ee-b8e9-d1aff4f804f9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsGross"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNet_01a0205d-efbb-7169-8401-5a495d3f6234" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsGross_01a0205d-efbb-78ee-b8e9-d1aff4f804f9" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_01a0205d-efbb-749f-884c-bbb415885128" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNet_01a0205d-efbb-7169-8401-5a495d3f6234" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_01a0205d-efbb-749f-884c-bbb415885128" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.protolabs.com/role/GoodwillandOtherIntangibleAssetsScheduleofAggregatedAmortizationExpenseDetails" xlink:type="simple" xlink:href="prlb-20260930.xsd#GoodwillandOtherIntangibleAssetsScheduleofAggregatedAmortizationExpenseDetails"/>
  <link:calculationLink xlink:role="http://www.protolabs.com/role/GoodwillandOtherIntangibleAssetsScheduleofAggregatedAmortizationExpenseDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNet_01a0205d-efbb-7d15-9edf-3a1acd7d1e9c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsNet"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths_01a0205d-efbb-7f79-bbbc-481b759f1bd2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNet_01a0205d-efbb-7d15-9edf-3a1acd7d1e9c" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths_01a0205d-efbb-7f79-bbbc-481b759f1bd2" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour_01a0205d-efbb-7a2a-9ff8-09ada1f7356e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNet_01a0205d-efbb-7d15-9edf-3a1acd7d1e9c" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour_01a0205d-efbb-7a2a-9ff8-09ada1f7356e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRemainderOfFiscalYear_01a0205d-efbb-7de3-95cc-ed811f0092bd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRemainderOfFiscalYear"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNet_01a0205d-efbb-7d15-9edf-3a1acd7d1e9c" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRemainderOfFiscalYear_01a0205d-efbb-7de3-95cc-ed811f0092bd" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_prlb_IntangibleAssetFiniteLivedEstimatedAmortizationExpenseAfterYearFour_01a0205d-efbb-71ea-b21b-fb831f321b67" xlink:href="prlb-20260930.xsd#prlb_IntangibleAssetFiniteLivedEstimatedAmortizationExpenseAfterYearFour"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNet_01a0205d-efbb-7d15-9edf-3a1acd7d1e9c" xlink:to="loc_prlb_IntangibleAssetFiniteLivedEstimatedAmortizationExpenseAfterYearFour_01a0205d-efbb-71ea-b21b-fb831f321b67" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo_01a0205d-efbb-73f4-914d-1d1bc23cd7c6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNet_01a0205d-efbb-7d15-9edf-3a1acd7d1e9c" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo_01a0205d-efbb-73f4-914d-1d1bc23cd7c6" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree_01a0205d-efbb-7cb8-973c-125cb99f6c89" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNet_01a0205d-efbb-7d15-9edf-3a1acd7d1e9c" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree_01a0205d-efbb-7cb8-973c-125cb99f6c89" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.protolabs.com/role/FairValueMeasurementsandMarketableSecuritiesDetails" xlink:type="simple" xlink:href="prlb-20260930.xsd#FairValueMeasurementsandMarketableSecuritiesDetails"/>
  <link:calculationLink xlink:role="http://www.protolabs.com/role/FairValueMeasurementsandMarketableSecuritiesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsFairValueDisclosure_01a0205d-efbb-7b5c-a23a-f28ebf03f30e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetsFairValueDisclosure"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_01a0205d-efbb-7a02-ac44-39a5d500f9e0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashAndCashEquivalentsFairValueDisclosure"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsFairValueDisclosure_01a0205d-efbb-7b5c-a23a-f28ebf03f30e" xlink:to="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_01a0205d-efbb-7a02-ac44-39a5d500f9e0" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_01a0205d-efbb-76fa-b884-73f77d362bd5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleSecuritiesDebtSecurities"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsFairValueDisclosure_01a0205d-efbb-7b5c-a23a-f28ebf03f30e" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_01a0205d-efbb-76fa-b884-73f77d362bd5" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.protolabs.com/role/FairValueMeasurementsandMarketableSecuritiesScheduleofShortTermandLongTermMarketableSecuritiesDetails" xlink:type="simple" xlink:href="prlb-20260930.xsd#FairValueMeasurementsandMarketableSecuritiesScheduleofShortTermandLongTermMarketableSecuritiesDetails"/>
  <link:calculationLink xlink:role="http://www.protolabs.com/role/FairValueMeasurementsandMarketableSecuritiesScheduleofShortTermandLongTermMarketableSecuritiesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis_01a09dab-9645-73fc-8f4e-0bb9804ff9b8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax_01a09dab-9645-70f3-af95-f9cb5f4940ee" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis_01a09dab-9645-73fc-8f4e-0bb9804ff9b8" xlink:to="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax_01a09dab-9645-70f3-af95-f9cb5f4940ee" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax_01a09dab-9645-788e-8f55-2a74dc8cc106" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis_01a09dab-9645-73fc-8f4e-0bb9804ff9b8" xlink:to="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax_01a09dab-9645-788e-8f55-2a74dc8cc106" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_01a09dab-9645-72b3-8429-0049e3e3224f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleSecuritiesDebtSecurities"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis_01a09dab-9645-73fc-8f4e-0bb9804ff9b8" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_01a09dab-9645-72b3-8429-0049e3e3224f" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.protolabs.com/role/FairValueMeasurementsandMarketableSecuritiesScheduleofAvailableForSaleDebtSecuritiesbyContractualMaturityDetails" xlink:type="simple" xlink:href="prlb-20260930.xsd#FairValueMeasurementsandMarketableSecuritiesScheduleofAvailableForSaleDebtSecuritiesbyContractualMaturityDetails"/>
  <link:calculationLink xlink:role="http://www.protolabs.com/role/FairValueMeasurementsandMarketableSecuritiesScheduleofAvailableForSaleDebtSecuritiesbyContractualMaturityDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_01a09dab-7fc6-7fc9-8782-6e5bd283411e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleSecuritiesDebtSecurities"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue_01a09dab-7fc6-7908-addc-bd172f9a6535" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_01a09dab-7fc6-7fc9-8782-6e5bd283411e" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue_01a09dab-7fc6-7908-addc-bd172f9a6535" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue_01a09dab-7fc6-7f81-a9a4-729203635b5f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_01a09dab-7fc6-7fc9-8782-6e5bd283411e" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue_01a09dab-7fc6-7f81-a9a4-729203635b5f" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.protolabs.com/role/InventoryDetails" xlink:type="simple" xlink:href="prlb-20260930.xsd#InventoryDetails"/>
  <link:calculationLink xlink:role="http://www.protolabs.com/role/InventoryDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryNet_01a0205d-efbb-7dfe-97c6-935df44eb3bb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InventoryNet"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryGross_01a0205d-efbb-7c45-acdf-449670a8ba62" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InventoryGross"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_InventoryNet_01a0205d-efbb-7dfe-97c6-935df44eb3bb" xlink:to="loc_us-gaap_InventoryGross_01a0205d-efbb-7c45-acdf-449670a8ba62" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryValuationReserves_01a0205d-efbb-786e-b898-4dab99d303fa" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InventoryValuationReserves"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_InventoryNet_01a0205d-efbb-7dfe-97c6-935df44eb3bb" xlink:to="loc_us-gaap_InventoryValuationReserves_01a0205d-efbb-786e-b898-4dab99d303fa" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.protolabs.com/role/AccumulatedOtherComprehensiveLossIncomeDetails" xlink:type="simple" xlink:href="prlb-20260930.xsd#AccumulatedOtherComprehensiveLossIncomeDetails"/>
  <link:calculationLink xlink:role="http://www.protolabs.com/role/AccumulatedOtherComprehensiveLossIncomeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_01a0205d-efbb-714f-91bf-7a7adf8fde46" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OciBeforeReclassificationsNetOfTaxAttributableToParent_01a0205d-efbb-7dda-b735-786aa7ae448d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OciBeforeReclassificationsNetOfTaxAttributableToParent"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_01a0205d-efbb-714f-91bf-7a7adf8fde46" xlink:to="loc_us-gaap_OciBeforeReclassificationsNetOfTaxAttributableToParent_01a0205d-efbb-7dda-b735-786aa7ae448d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent_01a0205d-efbb-71b4-9538-53612fdaae91" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_01a0205d-efbb-714f-91bf-7a7adf8fde46" xlink:to="loc_us-gaap_ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent_01a0205d-efbb-71b4-9538-53612fdaae91" xlink:type="arc"/>
  </link:calculationLink>
</link:linkbase>
