# ROI calculator

Canonical: https://fairleadhq.com/roi/


Compare modeled bug-fixing and unit-test economics over twelve months.

[Open the interactive calculator](https://fairleadhq.com/roi/) to change inputs and inspect the charts. This Markdown snapshot does not run scenarios submitted by an agent.

## Request a report

Submit your name, job title, company, corporate email and project name alongside all calculator parameters. Email consent is required and unchecked by default. Requests are saved for follow-up; no report is downloaded.

## Default inputs

| Parameter | Value | Meaning |
| --- | --- | --- |
| Lines of code | 1000000  | The codebase this team maintains. |
| Developers on the team | 11  | People who write and fix this code. |
| Developer salary a year | 150000 USD | All in cost of one developer. |
| Coverage today | 15 % | Where the codebase starts. |
| Time spent on unit tests | 20 % | Share of developer time that goes on writing them. It sets how many tests the team writes by hand, so it counts only with equal scope off. |
| Coverage wanted | 80 % | Where it should get to. |
| Value of a test | 233 USD | What one escaped bug costs you, per test that would have caught it. |
| Time spent fixing bugs | 25 % | Share of the team that goes on bugs rather than new work. |
| Net codebase growth a month | 3 % | Net increase in codebase size. Rewriting existing code does not count as growth. |
| Bugs per new commit | 21.5 % | How often a change brings a defect with it. It sets how many bugs come in each month. |
| Tokens a bug, local agent | 3 millions | What a local agentic tool burns on one fix. |

Equal scope is on: every approach is priced to deliver the same work. With equal scope off, output is limited by each approach’s modeled capacity.

## Default model results

- Unit tests, first year return: +429%
- Bug fixing, modeled ROI: +159%
- Estimated cost avoided over 12 months, both models: $1,009,107

## Bug fixing

- What the same bugs cost: Cumulative spend on fixing them.
- Bugs fixed: Every approach resolves the full bug load with added capacity.
- Bug-fixing cost avoided: Difference from manual cost at the selected comparison scope.
- Bugs still open: Added capacity absorbs the full bug load. No bugs remain unresolved.

## Unit tests

- How fast coverage arrives: Every approach is priced to deliver these same tests, so they all follow this one curve. What separates them is the cost of getting here.
- What it costs to get there: Cumulative spend on writing and keeping those tests.
- What that leaves you: Value of the bugs those tests prevent, net of what they cost.
- Developer time not spent: Cumulative hours, against writing the same tests by hand.

## Bug-fixing assumptions

Model assumptions: 7.023 hours of manual work per bug, $15 per successful Fairlead fix, 75% success and manual fallback for the rest. AI-augmented work assumes 10% less direct effort. Semi-autonomous work assumes 55% less direct effort and 75% success.

The cost model includes 15 minutes of human review per resolved bug in all four approaches, manual fallback, context switching and release overhead. It excludes QA acceptance, setup and infrastructure.

The projection starts with an initial month’s bug load, then adds new bugs in months 1 through 12. It includes thirteen monthly bug loads in total. Like-for-like adds capacity to resolve the full bug load. With it off, manual and assisted capacity includes review time. Agent paths assume capacity for human fallback.

ROI = (manual cost − Fairlead cost) / Fairlead cost.

## Limits

Results depend on the assumptions and inputs. Use your own costs and workload to assess applicability. Currency values are USD. Pricing and product availability are described separately in [pricing](https://fairleadhq.com/pricing/) and the [platform overview](https://fairleadhq.com/platform/).