A/B Test Calculator

Find out the sample size you need and how long to run your test before you launch.

Audience

Audience Size
Total audience available for the test.

Per Week

Baseline Conversion Rate
The current conversion rate of the control audience.

Expected Lift
The minimum % change you want to detect between the test and control audiences. Also called the Minimum Detectable Effect (MDE).

Test Setup

Test Audience
A 50/50 split is statistically most efficient, resulting in the shortest test duration.

Control Audience

50%

Test Type
One-sided: Detects if the test audience is better than control. Cannot detect negative impact.
Two-sided: Detects if the test audience is better OR worse than control. Requires a longer test duration.

Power

The probability that the test will detect the expected lift, if it is present. Standard is 80%.

Confidence

The probability that a detected lift is not due to random chance. Standard is 95%.
ABTestPro.com

Test Plan

The minimum audience size and test duration required to achieve statistical significance.

Estimated Test Duration
N/A
Minimum Required Audience
N/A
Target Power: 80% / Confidence: 95%
Audience Size
(Weekly)
50,000
Test
Split
50% / 50%
Baseline
Conv. Rate
1.2%
Expected
Lift
10%
Expected
Conv. Rate
-
ABTestPro.com

Statistical Power Sensitivity

Expected Lift
123456789101112
# of Weeks
ABTestPro.com

Technical Summary

Audience50,000 / Weekly
Baseline Conversion Rate1.2%
Expected Lift10%
Expected Conversion RateN/A
Expected ConversionsN/A
Test Split50% / 50%
Test TypeOne-sided
Power80%
Confidence95%
Standard Error
Z-Alpha
Z-Beta
Statistical Power per WeekN/A
Test Efficiency
Minimum Required Audience for TestN/A
Minimum Required Audience for ControlN/A
Total Minimum Required AudienceN/A
Test Durationundefined Weeks