A/B Test Sample Size Calculator
Compute the sample size per group for a two-proportion A/B test given baseline conversion, minimum detectable effect, confidence and power.
How to Use the A/B Test Sample Size Calculator
- Enter baseline conversion (%).
- Enter the minimum relative lift you want to detect.
- Pick confidence and power.
- Click Calculate.
使用例
- •Product experimentation.
- •Marketing test planning.
- •Peer-review experiment design.
計算式
n = [z_(1−α/2)·√(2p̄(1−p̄)) + z_(1−β)·√(p₁(1−p₁) + p₂(1−p₂))]² / (p₂ − p₁)².
よくある質問
Absolute vs relative lift?
Here MDE is a relative lift (e.g. 5% of a 10% baseline → 10.5% new). For absolute MDE, enter (absolute / baseline × 100).
What power should I pick?
80% is standard; 90% reduces false negatives but requires ~30% more sample.