👑 EXCLUSIVE TOOL
A/B Test Duration Calculator
Calculate exactly how long to run your A/B test to get statistically valid results. Stop calling tests too early and making decisions on noise.
📊 Test Parameters
Your current conversion rate. E.g., 3% means 3 out of 100 visitors convert.
The minimum relative improvement you want to detect. 10% MDE on 3% baseline = detecting a lift from 3.0% to 3.3%.
How many visitors per day will be allocated to EACH variation (control + treatment).
More variations require more traffic per variation or longer test duration.
Probability that a detected effect is real, not random chance. 95% is the industry standard.
Probability of detecting a real effect when one exists. 80% is standard; 90% for important decisions.
Two-sided detects both improvements and regressions. One-sided has more power but only detects changes in one direction.
Duration by MDE (at your traffic level)
📋 Sensitivity Matrix
How duration changes across different MDEs and traffic levels.