Test Duration Calculator

Calculate how long your A/B test needs to run to achieve statistical significance. Enter your traffic and conversion data to get started.

Traffic Metrics

Total visitors who will see your experiment each week

Current weekly conversions (used to calculate baseline rate)

Including control (min: 2, max: 10)

Statistical Parameters

Or enter directly if you know your conversion rate

Relative improvement you want to detect (e.g., 10% = 5% to 5.5%)

Confidence level (typically 90%, 95%, or 99%)

Probability of detecting a true effect (typically 80%)