A/B Test Significance Calculator

Enter control and variant visitors and conversions to check statistical significance, p-value, and lift. Updates instantly.

Control (A)
Variant (B)
—Control rate
—Variant rate
—Lift
—p-value
—Significant?

How to use

  1. Enter visitor and conversion counts for your control (A) and variant (B).
  2. Select your confidence level (95% is standard).
  3. Check whether the result is statistically significant and review the lift.

Frequently asked questions

What is statistical significance in A/B testing?

Statistical significance tells you whether the difference between your control and variant conversion rates is likely real or just random noise. A p-value below 0.05 (at 95% confidence) means there is less than a 5% chance the result is due to chance.

What p-value should I use?

95% confidence (p < 0.05) is the industry standard. For high-stakes decisions, use 99% confidence (p < 0.01). For exploratory tests, 90% may be acceptable.

What is lift?

Lift is the relative improvement of the variant over the control. If control converts at 2% and variant at 2.5%, lift is +25%.

How many visitors do I need for A/B testing?

It depends on your baseline conversion rate and the minimum detectable effect. Lower conversion rates and smaller expected improvements require larger sample sizes.

Last updated

Powered by maratool