A/B Test Duration Calculator
How many days your A/B test needs to run and when it ends, from your rate, target effect, traffic and number of variations.
Open tool →Free calculators, generators and checkers that run right in your browser. No signup, no install, with the math explained.
How many days your A/B test needs to run and when it ends, from your rate, target effect, traffic and number of variations.
Open tool →How many visitors per variation and how many days your A/B test needs. Free, live, with the math behind it explained.
Open tool →Paste visitors and conversions for A and B and see if the result is real: p-value, lift, confidence interval and a plain verdict.
Open tool →Find the probability that B beats A and the expected loss of your A/B test, with no p-value. Free, live, with the Bayesian math explained.
Open tool →Confidence interval for a conversion rate or for the difference between A and B. Free, live, with Wilson, Wald and the formula explained.
Open tool →See what your A/B testing program is worth: first-year ROI, incremental revenue and net gain. Free, live, with the math explained.
Open tool →Find the smallest effect your traffic can detect in an A/B test. Enter your rate, visitors and duration and see the relative and absolute MDE.
Open tool →Calculate the p-value of your A/B test (two-proportion z-test), one or two-sided, and see if it rejects the null at 90%, 95% and 99% confidence.
Open tool →Find out if your A/B test's traffic split is broken (SRM). Paste the visitors per variation and see the chi-square, the p-value and a plain verdict.
Open tool →Find the statistical power of the A/B test you ran: the chance of detecting the effect with the sample you had. Free, live, with the formula explained.
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