Free A/B Test Calculator
A/B Test Calculator
Plan your experiments with precision. Calculate sample sizes before testing or verify statistical significance after.
Test Parameters
Enter your experiment parameters to calculate required sample size.
0.1%50%
1%100%
Results
Sample Size per Variant
8,158
Total: 16,316 visitors
Estimated Test Duration
17 days
Based on 1,000 daily visitors
Expected Change
5%6.00%(+20%)
Sample Size
Calculate the minimum number of visitors needed before starting your experiment.
Statistical Power
80% power means 80% chance of detecting a real effect if it exists.
Two-Tailed Test
Detects both positive and negative changes in your conversion rate.