Cloud Migration Cost Calculator
Cost a migration wave from the 6 Rs — rehost, replatform, refactor, repurchase, retire and retain — with dual-run overlap.
About Cloud Migration Cost Calculator
Every application is bucketed into one of the 6 Rs and given an hours-per-application figure, because a lift-and-shift and a refactor differ by an order of magnitude in effort. The hours become cost at your blended rate, and dividing the same hours by real team capacity gives the elapsed timeline — which is usually the number that surprises people, not the money. Migrations overrun because retire and retain decisions are made late and the dual-run overlap stretches, so both estates bill in full for months. Sizing the overlap explicitly turns it into a deadline instead of a surprise; these are planning estimates, not a quotation.
Formula
Cloud Migration Cost
hours = Σ (applications in each R × hours for that R); cost = hours × blended rate + dual-run months × monthly dual-run cost + tooling; elapsed months = hours ÷ (engineers × productive hours each).
- 6 Rs
- Rehost, replatform, refactor, repurchase, retire and retain
- dual-run
- The period you pay for both the old and the new estate
- productive hours
- Hours per engineer per month genuinely available for migration work
Worked example
With the default values below, Cloud Migration Cost Calculator returns Total Migration Cost of $764,160.00. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Applications to rehost (lift and shift)accepts 0–5,000 apps
- 40 apps
- Applications to replatformaccepts 0–5,000 apps
- 15 apps
- Applications to refactoraccepts 0–5,000 apps
- 6 apps
- Applications to repurchase as SaaSaccepts 0–5,000 apps
- 5 apps
- Applications to retireaccepts 0–5,000 apps
- 8 apps
- Applications to retain on-premisesaccepts 0–5,000 apps
- 6 apps
- Hours per rehosted applicationaccepts 1–4,000 hours
- 40 hours
- Hours per replatformed applicationaccepts 1–4,000 hours
- 120 hours
- Hours per refactored applicationaccepts 1–20,000 hours
- 400 hours
- Hours per repurchased applicationaccepts 1–4,000 hours
- 80 hours
- Hours per retired applicationaccepts 0–1,000 hours
- 16 hours
- Blended engineering rateaccepts 0–1,000 USD/hour
- 95 USD/hour
- Tooling, training and partner feesaccepts 0–10,000,000 USD
- 43,000 USD
- Months running both estatesaccepts 0–60 months
- 3 months
- Monthly cost of the estate you have not switched offaccepts 0–5,000,000 USD/month
- 40,000 USD/month
- Engineers on the migrationaccepts 1–500 people
- 6 people
- Productive migration hours per engineer per monthaccepts 20–176 hours
- 130 hours
Results
- Total Migration Cost
- $764,160.00
- Engineering Hours
- 6,328 hours
- Engineering Cost
- $601,160.00
- Dual-Run Cost
- $120,000.00
- Applications Actually Moving
- 66 apps
- Cost per Migrated Application
- $11,578.18
- Elapsed Delivery Time
- 8.1 months
- Applications in Scope
- 80 apps
Step by step
- 1Values used
- 2Cloud Migration Cost
- 3Total Migration Cost= 764,160.00
- 4Engineering Hours= 6,328 hours
- 5Engineering Cost= 601,160.00
- 6Dual-Run Cost= 120,000.00
- 7Applications Actually Moving= 66 apps
- 8Cost per Migrated Application= 11,578.18
Assumptions and limits
- The result is derived only from the 17 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax or compounding frequency into account.
- Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
Frequently Asked Questions
How is Cloud Migration Cost calculated?
hours = Σ (applications in each R × hours for that R); cost = hours × blended rate + dual-run months × monthly dual-run cost + tooling; elapsed months = hours ÷ (engineers × productive hours each). Every application is bucketed into one of the 6 Rs and given an hours-per-application figure, because a lift-and-shift and a refactor differ by an order of magnitude in effort. The hours become cost at your blended rate, and dividing the same hours by real team capacity gives the elapsed timeline — which is usually the number that surprises people, not the money.
Why does Cloud Migration Cost matter?
Migrations overrun because retire and retain decisions are made late and the dual-run overlap stretches, so both estates bill in full for months. Sizing the overlap explicitly turns it into a deadline instead of a surprise; these are planning estimates, not a quotation.
What values do I need to enter?
This calculator takes 17 inputs: Applications to rehost (lift and shift), Applications to replatform, Applications to refactor, Applications to repurchase as SaaS, Applications to retire, Applications to retain on-premises, Hours per rehosted application, Hours per replatformed application, Hours per refactored application, Hours per repurchased application, Hours per retired application, Blended engineering rate, Tooling, training and partner fees, Months running both estates, Monthly cost of the estate you have not switched off, Engineers on the migration, Productive migration hours per engineer per month. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.
Why does retiring an application still cost hours?
Decommissioning needs owner sign-off, data archived to meet retention rules, licences cancelled, DNS and monitoring cleaned up and evidence kept for auditors. It is cheap per application but it is never free, and skipping it leaves zombie infrastructure billing forever.