ERP total cost of ownership calculator
Put an ERP subscription and implementation next to custom software for the same processes, and see the cost each year.
Free, runs in your browser, no sign-up. Updated 2026-10-25.
Result
Enter your vendor's price for: ERP. ERP over 7 years so far: $0; Custom: $403,300.
- ERP, 7 years
- Enter price
- Custom, 7 years
- $403,300
- ERP, year one
- $0
- Custom, year one
- $159,000
| Year | ERP | Custom | ERP total | Custom total |
|---|---|---|---|---|
| 1 | $0 | $159,000 | $0 | $159,000 |
| 2 | $0 | $39,500 | $0 | $198,500 |
| 3 | $0 | $39,900 | $0 | $238,400 |
| 4 | $0 | $40,400 | $0 | $278,800 |
| 5 | $0 | $40,900 | $0 | $319,700 |
| 6 | $0 | $41,500 | $0 | $361,200 |
| 7 | $0 | $42,100 | $0 | $403,300 |
Repeating costs grow 5% a year for erp and 5% for custom. One-off costs fall in year one.
Assumptions
Every number the result depends on, and where it comes from. Change any value and the result updates.
| Assumption | Value | Source |
|---|---|---|
| Yearly ERP price increase | % | OceanLab assumption. Placeholder. Check the vendor's renewal terms.Reviewed 2026-10-25 |
| Yearly maintenance on custom software, share of build cost | % | OceanLab assumption. No primary source. Bug fixes, dependency and security updates and small changes on software you own. Raise it for fast-changing products.Reviewed 2026-10-25 |
| Yearly growth in custom running costs | % | OceanLab assumption. Placeholder for usage growth and price rises. Use your own forecast.Reviewed 2026-10-25 |
Send this comparison to OceanLab
Opens an email to OceanLab with this result and a link to your inputs. Nothing is sent until you press send, and there is no sign-up.
How this is calculated
ERP, per year: users × subscription per user, growing by a yearly percentage, plus support and add-ons. Implementation, customisation and integrations fall in year one.
Custom, per year: the build cost in year one, then hosting and your team, plus yearly maintenance as a share of the build cost from year two.
The ERP side starts empty because subscription and partner prices are quoted per company. Enter your vendor's quote to compare.
Questions about this tool
Why are the ERP prices empty?
ERP pricing depends on modules, users and the partner, and most vendors quote it. Enter what you were quoted.
What is usually missed in ERP budgets?
Customisation to fit your processes, integrations with other systems, data migration and the partner retainer after go-live.
When does custom software make sense instead?
When only a few processes matter and an ERP would force you to change how they work, or when per-user pricing grows faster than the business.
Is anything I enter sent anywhere?
No. The tool runs in your browser and there is no sign-up. Nothing leaves the page unless you choose to email your result to OceanLab.
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