Calculator / 05

A/B test significance, solved.

Two-proportion z-test for conversion rate comparison. p < 0.05 = 95% confidence.

Start from a preset

Inputs

Visitors — variant A

Conversions — variant A

Visitors — variant B

Conversions — variant B

∎Statistically significant lift at 95% confidence. Ship B.

Outputs

Rate A

10.00%

variant A conversion

Rate B

12.00%

variant B conversion

Lift

20.00%

relative change vs A

p-value

0.0432

significant

Formula · z-statistic

z = (p̂ᵦ − p̂ₐ) ÷ SE

SE = √(p(1−p)(1/nₐ + 1/nᵦ))

Formula · p-value

p = 2 · (1 − Φ(|z|))

two-tailed normal CDF