Sample Size Calculator

Calculate the minimum number of visitors needed to achieve statistical significance in your A/B test.

Test Parameters

Baseline Conversion Rate (%)

The current conversion rate of your control group.

Minimum Detectable Effect - Relative (%)

The minimum relative change you want to be able to detect.

Statistical Power

Significance Level

8,149

per variation

16,298

Total traffic needed

Baseline: Look at your analytics to find the current conversion rate of the funnel step you are testing.
MDE (Relative): The smaller the MDE, the more traffic you need to prove it wasn't a fluke. A 20% MDE on a 5% baseline means you aim to reach 6%.
Duration: Divide the "Total traffic needed" by your daily visitor count to find out how many days the test needs to run. (Aim for 1-4 weeks).