Legacy ERP On-Premises Run Cost Calculator
The cost of keeping GP or AX on-premises is spread across infrastructure, licences, people and backup budgets. Seeing it as one number makes the comparison with a subscription fair.
Your numbers
Hardware depreciation or hosting, power, OS licence and backup agent.
Your results
Excludes refresh capex spikes, security tooling and internal overhead allocations. Add them to server cost if material.
Five-year cost vs inflation
Sweeps Annual cost inflation from 0 to 15, holding your other inputs fixed.
Optional infrastructure baseline review
Have us help check that your run cost baseline is complete.
Optional. The tool and every export work without this. No spam.
How to use it
Collect numbers from different owners: infrastructure for servers and DR, the DBA for effort, procurement for SQL and maintenance. Enter admin effort as full-time equivalents, even if split across several people. Include test and development servers because AX typically needs build and test environments in addition to production.
The method
Annual run cost is infrastructure plus SQL licence plus admin labour plus disaster recovery plus vendor maintenance. Infrastructure is server count times cost per server. The five-year figure sums a growing series: run cost times (one plus inflation) to the fifth, minus one, divided by the inflation rate.
Using it in a comparison
Take the annual run cost and compare it with a subscription quote plus the remaining infrastructure you cannot retire. Common mistakes are leaving out admin time because it is salaried, and excluding DR because it is shared. If a shared cost falls only partly away, enter the portion that truly goes away.
- Include test and build servers
- Allocate shared costs honestly
- Add hardware refresh in cost per server
- Feed the result into the payback calculator
Frequently Asked Questions
Why include admin labour?
Because staff time spent patching, tuning and supporting legacy systems is a real cost, and a cloud move often releases it for other work. Count it only to the extent it can be redeployed.
Does this cover hardware refresh?
Fold it into cost per server by spreading the purchase over its useful life. A server bought for 24,000 and used for four years adds 6,000 a year.
Is five years the right horizon?
It is common for business cases and matches typical subscription terms and hardware cycles. Change the inflation slider to see sensitivity.
What if I already run in a hosted data centre?
Enter the hosting fee per server in the server cost field and set admin effort to the part you still do.
Netray can help inventory what actually runs and who uses it. The calculator above works entirely on its own.
Related Tools
ERP Migration Payback and NPV Calculator
Calculates payback period, net present value and ROI for a GP or AX replacement from investment, run-cost savings and productivity gains.
Microsoft DynamicsGP to Business Central Licence Cost Calculator
Turns your GP full and limited user counts into a Business Central subscription estimate and compares it with what you pay for GP today.
Microsoft DynamicsDynamics GP Unsupported Risk Exposure Calculator
Adds up support fees, compensating controls, manual workarounds and expected incident loss to show what another year on Dynamics GP really costs.
ERP OperationsLegacy ERP Database Growth and Archive Savings Calculator
Projects database size forward, applies an archive share and prices the storage and backup copies you avoid.
More ERP Migration & Selection tools
See all- ERP TCO Comparison Calculator (5-Year)
- ERP Migration Risk Assessment
- Data Migration Effort Calculator
- ERP Selection Scorecard for Manufacturers
- ERP Go-Live Readiness Checklist
- ERP Change Management Readiness Assessment
- ERP Integration Complexity Calculator
- Cloud vs On-Premise ERP Cost Calculator
- ERP Upgrade vs Replace Assessment