A/B Testing Token Usage Calculator
Estimate token consumption and API cost for control and variant groups in an A/B test, including the incremental token impact of the variant.
Overview
Use this A/B Testing Token Usage Calculator to estimate the total tokens and token-related API cost used by your control and variant groups. Enter group sizes, average requests per user, average tokens per request, and your blended price per million tokens to see the variant's incremental usage impact.
How it works
The calculator multiplies each group's users by average requests per user to estimate requests. It then multiplies those requests by the relevant average tokens per request and combines both groups for total test usage. To measure the variant's impact, it compares actual test usage with a baseline where every observed request used the control token rate. Token totals are converted to an estimated cost using the price you enter per one million tokens.
How to use this calculator
- 1Enter the number of users in the control group.
- 2Enter the number of users exposed to the variant.
- 3Add the average number of token-consuming requests per user.
- 4Enter average total tokens per request for the control and variant.
- 5Enter your blended cost per one million tokens.
- 6Review total test usage and the variant's estimated incremental cost.
Example Calculation
Control group users
5000
Variant group users
5000
Average requests per user
3
Control tokens per request
1200
Variant tokens per request
1500
Cost per 1 million tokens
$5
Total test token usage
/40,500,000 tokens
With 5,000 users in each group and three requests per user, the test uses an estimated 40,500,000 tokens and costs about 202.50. The higher-token variant adds about 4,500,000 tokens, or 22.50, versus using control for all test requests.
Frequently asked questions
What is incremental token usage in an A/B test?
It is the difference between actual test token use and the estimated use if the variant-group requests had used the control configuration instead. A negative value indicates a token reduction.
Should I include both input and output tokens?
Yes. Use the average total billed tokens per request whenever possible. If input and output tokens have different prices, enter a blended cost per million tokens that reflects your typical mix.
Why might the variant use more tokens than the control?
A variant may use longer prompts, more retrieved context, additional tool calls, a different model, or generate longer responses. Measuring actual request averages produces the most useful estimate.
Can I use unequal A/B test group sizes?
Yes. Enter the observed or planned user count for each group. The calculator estimates usage separately before combining the results.
Does this calculator include API fees beyond tokens?
No. It estimates token-related cost using your entered blended token price. Add other charges separately unless they are already included in that rate.
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Assumptions and warnings
Assumptions
- Each user in both groups makes the same average number of token-consuming requests.
- Average tokens per request are representative of the full test period.
- The cost per million tokens is a blended rate that covers the token types and model usage in your test.
- The incremental comparison assumes variant-group requests would otherwise have used the control configuration.
- Results are estimates and exclude non-token charges such as platform, storage, caching, or tool-call fees unless included in your entered price.
Warnings
- Token pricing, token counting methods, and billed input and output rates can vary by model and provider.
- This calculator provides an operational cost estimate only and is not financial advice.