A/B/C Test Calculator
Calculate the required sample size and test duration for three variants,
with built-in correction for multiple comparisons.
Audience
Audience SizeTotal audience available for the test.
Total audience available for the test.
Per Week
Baseline Conversion Rate - Group AThe current conversion rate of the control audience (Group A).
The current conversion rate of the control audience (Group A).
Group A
Expected Lift - Group BThe minimum % change you want to detect for Group B compared to Group A.
The minimum % change you want to detect for Group B compared to Group A.
Group B
Expected Lift - Group CThe minimum % change you want to detect for Group C compared to Group A.
The minimum % change you want to detect for Group C compared to Group A.
Group C
Test Setup
Audience SplitAn equal split (33.3% each) is statistically most efficient for A/B/C tests.
An equal split (33.3% each) is statistically most efficient for A/B/C tests.
Group A
Group B
Group C
Test TypeOne-sided: Detects if test groups are better than control. Cannot detect negative impact.Two-sided: Detects if test groups are better OR worse than control. Requires a longer test duration.
One-sided: Detects if test groups are better than control. Cannot detect negative impact.
Two-sided: Detects if test groups are 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%.