Sample size calculator for A/B testing
Sample size & test length calculator
The probability that the result is not a false positive. Default is 90.
The probability that the result is not a false negative. Default is 80.
Total sample size
How we calculate
This calculator is used to compute the sample size for your variations and the test length and is based on the SiteGainer Stats Engine which employees the Frequentist methodology known as a one-tailed Z test for the difference between two proportions.
When testing one or more variations, the calculator adjusts the sample size using the Bonferroni correction.
For more information on why we are using one-tail tests, read Common misconceptions about one-tailed vs. two-tailed tests
Please use our chat or e-mail firstname.lastname@example.org to get assistance on how to determine your sample size.