How this calculator works
| Metric | Formula |
|---|---|
| Developer time cost | developers × cost per developer × time lost % |
| Incident cost | incidents per month × 12 × cost per incident |
| Saving after paydown | (time cost + incident cost) × debt removed % |
| Payback (months) | paydown cost ÷ (yearly saving ÷ 12) |
Worked example
With these inputs:
- Currency: USD ($)
- Developers: 10
- Loaded cost per developer per year: 90,000
- Time lost to technical debt: 25%
- Production incidents per month caused by fragile code: 3
- Average cost per incident: 1,500
- Debt removed by a paydown project: 50%
- Cost of the paydown project: 80,000
Cost of technical debt per year: $279,000. Technical debt costs about $279,000 a year — the equivalent of 2.5 full-time developers plus incidents.
| Developer time lost | $225,000 (2.5 FTE) |
|---|---|
| Incident cost per year | $54,000 |
| Saving per year after paydown | $139,500 |
| Developers freed for new features | 1.3 FTE |
| Payback period | 6.9 months |
| 3-year net benefit | $338,500 |
Open this example in the calculator
How much time does technical debt take?
In Stripe’s Developer Coefficient survey, developers reported spending about 42% of their working week on maintenance work, including dealing with technical debt and bad code. Your team’s figure may be lower or higher — ask them, or check how much sprint time goes to bugs and unplanned work.
Signs technical debt is costing you
- Simple changes take days because many parts of the system are affected.
- Releases are manual, infrequent and stressful.
- The same kinds of bugs come back after being fixed.
- Few automated tests, so developers are afraid to change code.
- Old frameworks or libraries that no longer receive security updates.
- Only one or two people understand key parts of the system.
How to pay down technical debt
- Measure first: track time spent on bugs, unplanned work and incidents.
- Prioritise modules that change often and cause the most problems.
- Add automated tests before refactoring so behaviour stays the same.
- Reserve a steady share of each sprint (often 15–20%) for improvements.
- Upgrade frameworks and dependencies on a schedule instead of all at once.
Open this calculator with your numbers
Every option can be set in the web address, so you can bookmark a scenario or send it to a colleague. AI assistants such as ChatGPT, Gemini, Claude and Perplexity can use the same parameters to open this calculator with your numbers and the result already on the page.
| Parameter | What it sets | Accepted values |
|---|---|---|
currency |
Currency | one of USD, INR, AED, GBP, EUR |
developers |
Developers | number from 1 to 10000, default 10 |
developer_cost |
Loaded cost per developer per year | number from 0 to 10000000 (in the chosen currency), default 90000 |
debt_time |
Time lost to technical debt | number from 0 to 90 (%), default 25 |
incidents |
Production incidents per month caused by fragile code | number from 0 to 1000, default 3 |
incident_cost |
Average cost per incident | number from 0 to 100000000 (in the chosen currency), default 1500 |
reduction |
Debt removed by a paydown project | number from 0 to 100 (%), default 50 |
paydown_cost |
Cost of the paydown project | number from 0 to 1000000000 (in the chosen currency), default 80000 |
Also available as plain text for AI assistants and a free JSON API (OpenAPI spec).
Sources
Last reviewed by the Infikey Technologies team.
Disclaimer
This calculator is provided free for general information and planning only. Results are estimates based on the inputs you enter and the assumptions described on this page, reference data such as published prices may change, and actual costs and outcomes will differ. Nothing on this page is financial, legal, tax, investment or other professional advice. Infikey Technologies Private Limited, Infikey Technologies LLC and their directors, employees and affiliates make no warranty, express or implied, about the accuracy, completeness or suitability of this tool or its results, and accept no liability for any loss or damage, direct or indirect, arising from its use or from reliance on its results. Verify all figures independently and seek professional advice before making any decision. Use of this tool is at your own risk.