Free A/B Testing Significance Calculator

Input visitor counts and conversion numbers to calculate statistical significance, P-value, confidence intervals, and get clear launch advice.

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How to Use

Z-test conversion rate analysis

P-value significance check

Confidence interval output

Plain-English launch advice

FAQ

What P-value should I aim for?▾

A P-value below 0.05 (95% confidence) is the standard threshold for statistical significance in A/B testing. Below 0.01 (99% confidence) is even stronger.

How much traffic do I need?▾

It depends on your baseline conversion rate and the minimum detectable effect. Generally, you need at least 100 conversions per variant for reliable results.

Can I use this for multivariate tests?▾

This calculator is designed for two-variant A/B tests. For multivariate testing, use ANOVA-based tools.