A/B Testing API Cost (Monthly) Calculator FAQ
Answers to common questions about estimating A/B test API calls, monthly usage costs, pricing inputs, and result accuracy.
Use these answers to choose realistic inputs and understand what the monthly A/B testing API cost estimate includes and excludes.
General calculator questions
Basic questions about the purpose and use of the estimate.
What does the A/B Testing API Cost (Monthly) Calculator estimate?
It estimates variable monthly API usage cost for an experiment using traffic, test allocation, calls per test visitor, billing days, and price per million calls.
Is this an estimate of the full A/B testing platform cost?
No. It estimates API usage only. Fixed subscriptions, support plans, implementation work, taxes, and other charges are not included.
Can I use this calculator for feature flags as well as A/B tests?
Yes, if you can estimate the visitors evaluated, billable calls per visitor, and an applicable price per million calls.
What currency does the calculator use?
It uses the currency of the price you enter. Keep the price and displayed result in the same currency.
Traffic and call inputs
How to select traffic, allocation, and call-volume assumptions.
What should I enter as average daily visitors?
Use the average daily users or visitors who could be evaluated by the experiment before applying the experiment traffic percentage.
Should I include visitors who are not assigned to a variant?
Include them only if they still generate billable experiment or feature-flag calls. Otherwise, use the share actually evaluated by the test.
What counts as API calls per visitor?
This can include assignment, configuration retrieval, flag evaluation, exposure logging, conversion events, and other billable requests in the user journey.
How do repeated visits affect the estimate?
If repeat sessions create new billable calls, reflect them in a higher average calls-per-visitor input.
Should bot traffic be included?
Include it only when it can trigger billable calls and is expected to be part of the provider's metered usage.
Pricing and formula questions
How the calculator converts API calls into a cost estimate.
What is the monthly API cost formula?
Monthly cost equals daily visitors times test allocation times billing days times calls per visitor, divided by one million, then multiplied by cost per million calls.
Why does the formula divide by one million?
The price input is stated per one million calls, so total calls must be converted into millions before applying that price.
Can I enter a discounted effective API price?
Yes. If you know an effective price that reflects your expected pricing arrangement, enter it consistently as the cost per million calls.
Does the calculator account for included free calls?
No. To account for included usage, reduce the billable call estimate or use an adjusted effective price outside the basic calculation.
Does the calculator handle tiered API pricing?
No. It uses one constant price per million calls. Estimate tiers separately if the provider changes rates at volume thresholds.
Accuracy and interpretation
Reasons calculated results can differ from measured provider usage.
Why might actual API costs differ from the estimate?
Traffic changes, retries, cache behavior, event volume, rounding, free quotas, pricing tiers, and provider billing rules can all change the billed amount.
How often should I update the estimate?
Update it when traffic, allocation, call patterns, billing days, or provider pricing change materially.
Is the average daily API cost an actual daily charge?
It is a monthly average. Actual daily usage can be higher or lower depending on traffic patterns.
Can I compare two experiment designs with this calculator?
Yes. Run each design with its own allocation and calls-per-visitor assumptions, then compare estimated calls and variable cost.
How is monthly A/B testing API cost calculated?
Multiply daily visitors by test allocation, billing days, and calls per test visitor. Divide by one million and multiply by the price per million calls.
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