A/B Test Sample Size

Calculate A/B Test Sample Size instantly. Free online calculator with the exact formula, a worked example, and metric units. No signup required.

A/B Test Sample Size

Base conversion
MDE (rel.)
α
Sample per group
14,735
p₁=0,1, p₂=0,11α=0.05, power=80%Calculate A/B Test Sample Size instantly. Free online calculator with the exact formula, a worked example, and metric units. No signup required.

More about: A/B Test Sample Size

What it calculates

The “A/B Test Sample Size” calculator computes Sample per group from 3 parameters: base conversion, mde (rel.), α.

A core calculation for studying, engineering tasks, and checking solutions.

Example calculation

With parameters Base conversion = 0.1, MDE (rel.) = 0.1, α = 0.05 the result is 14,735 (p₁=0,1, p₂=0,11).

How to use

  1. Enter the parameter values — every field above is adjustable with a slider.
  2. The result and related metrics are calculated automatically as you type.
  3. Use the additional metrics shown (if any) where needed.
  4. Copy the result or bookmark the page.

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