Split — A/B Test Significance Calculator

Experiment Data

Control —%

Visitors

Conversions

Variant —%

Visitors

Conversions

Confidence level

95%

Examples:

Conversion Lift

—

relative

p-value

—

Z-score

—

standard deviations

Power

—

test sensitivity

Conversion rate comparison

Control

—

Variant

—

95% confidence interval for the difference (variant − control)

How to read this: The p-value is the probability of seeing this difference (or larger) if there were truly no difference between variants. Below your confidence threshold (0.05), the result is statistically significant. Power reflects the chance the test would detect a real effect of this size — above 80% is solid.

Sample Size Planner

Baseline conversion rate (%)

Minimum detectable lift (%)

Confidence level

95%

Statistical power

80%

— visitors per variant

Enter your baseline and the smallest lift worth detecting.

Experiment Data

Sample Size Planner

Saved Experiments