Frequentist sample size calculator
Plug in your numbers below to learn how many visitors you need to get reliable results
Enter your current conversion rate as a percentage (e.g., 10 for 10%).
The smallest absolute difference in conversion rate you want to detect (e.g., 2 for a 2 percentage point increase).
Probability of a Type I error (false positive). Common values are 0.05 (95% confidence).
Probability of a Type II error (false negative). 0.20 means 80% power.
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