A/B Test Calc

v1.0.0

Calculate statistical significance, sample size, and power for A/B tests

Calculates A/B test sample sizes, statistical significance, and confidence intervals using a two-proportion z-test with normal approximation.

How to use

→Switch between Significance Calculator and Sample Size Calculator using the mode buttons at the top.
→For significance testing, enter visitor and conversion counts for both control (A) and variant (B).
→For sample size planning, set your baseline rate, minimum detectable effect, power, and confidence level.
→Enter daily traffic to estimate how many days your experiment needs to run.

Visitors

Conversions

Visitors

Conversions

✅ Statistically significant at the 95% confidence level

Control Conversion Rate

1.200%

Variant Conversion Rate

1.550%

Relative Lift

+29.17%

Z-Score

2.1252

P-Value

0.025364

Confidence Level

97.46%