A/B Test Significance Calculator

Determine the statistical significance of your test results

Unhinged Mode

Results

Control conversion rate
Variant conversion rate
Statistical significance
P-value
Relative lift
Absolute lift

How this works

This calculator uses a two-proportion z-test to determine whether the difference between your variant and control conversion rates is statistically significant.

z = (p₂ - p₁) / √[p̂(1-p̂)(1/n₁ + 1/n₂)]

Where:

  • p₁ is the control conversion rate
  • p₂ is the variant conversion rate
  • is the pooled proportion: (x₁ + x₂) / (n₁ + n₂)
  • n₁, n₂ are the sample sizes for control and variant

The p-value represents the probability of observing a difference at least as extreme as what you got, assuming there's no real difference between the variants. A p-value below your significance threshold (e.g., 0.05 for 95% significance) indicates a statistically significant result.