Sample Size Calculator
Determine required sample size for your A/B test
Quick Start: Choose a Scenario
Inputs
Configure your experiment parameters
5.0 %
Your current conversion rate before the experiment
Minimum Detectable Effect (MDE)
Selected: +5.0%
MDE is the minimum relative improvement you want to detect. A 5% MDE on an 8% baseline means detecting a change to 8.4%.
Statistical Power
Selected: 80
Enter your daily visitors to estimate runtime
Sample Size per Variant
0
At your baseline of 5.0%, detecting a 5.0% relative uplift (to 5.25%) requires ~122.1K users per variant.
Total Sample Needed
0 visitors
Combined sample across both variants (control + treatment)
Summary
Baseline rate 5.0%
Minimum detectable effect +5.0% relative
Expected variant rate 5.25%
Statistical power 80%
Confidence level 95%