What does a useful
AI outcome cost?
Put the whole batch in the numerator. Put acceptable outcomes in the denominator.
Illustrative planning tool · No model rankings
Use totals for one evaluation window. Include every attempt and retry, including those that failed. Define success before comparing designs; an agent saying “done” is not an acceptance check.
The starting numbers are invented examples from The cost of a completed task. Replace them with your own measurements. All amounts are USD; convert other currencies before entering them.
From your inputs
Cost and completion, together.
A lower cost per success does not establish equivalent quality, safety, latency, or suitability. Review the acceptance rule and excluded costs.
The method
Total included cost = model + tools + infrastructure + (review minutes × hourly human cost ÷ 60).
Cost per successful task = total included cost ÷ successful tasks. If no tasks succeed, this value is undefined: report “no successful completions.”
Use actual batch totals where possible. Review includes remediation and verification if you choose to include them. Shared overhead, acquisition costs, setup work, and other categories are excluded unless you allocate them explicitly. Avoid double-counting costs already bundled in another charge.
A worked example
Two invented designs attempt the same 100 tasks under the same acceptance rule. Human review and infrastructure are excluded.
| Metric | Design A | Design B |
|---|---|---|
| Total cost | $3.00 | $5.00 |
| Successful tasks | 40 | 90 |
| Cost per success | $0.075 | About $0.0556 |
Design A spends less overall; Design B costs less per acceptable result. Neither is a universal winner. Use this calculation alongside an evaluation of your application's requirements.
Inspect the assumptions
This is arithmetic on supplied values, not a price forecast or a measured model evaluation. Success rates are inputs. The calculator does not assume independent retries or estimate how reliability changes with more attempts. Read the source-backed cost guide and inspect the formula and worked example.