A/B Test Significance Calculator
Enter your control and variant data to check for statistical significance.
Control (A)
Variant (B)
How it works
This calculator uses a two-proportion Z-test to determine whether the difference between your control and variant conversion rates is statistically significant.
A result is considered significant at 95% confidence when the absolute Z-score exceeds 1.96, meaning there is less than a 5% probability the difference is due to chance.
p1 = control conversions / control visitors
p2 = variant conversions / variant visitors
pooled = (c_conv + v_conv) / (c_vis + v_vis)
SE = sqrt(pooled * (1 - pooled) * (1/n1 + 1/n2))
z = (p2 - p1) / SE
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