Pevlika Browser Apps

A/B Test Sample Size Calculator

Visitors needed per variant to detect a conversion lift.

Runs in your browser — nothing is uploaded
Relative lift, e.g. 10% means 5% → 5.5%.
Effect is
Test

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How to use A/B Test Sample Size Calculator

  1. Enter your values — the unit for each field is shown next to it.
  2. The result updates instantly as you type.
  3. Copy the results, or change inputs to compare scenarios.

Formula & assumptions

n = (z₁₋α/2·√(2p̄(1 − p̄)) + z₁₋β·√(p₁(1 − p₁) + p₂(1 − p₂)))² / (p₂ − p₁)²

Conversion Rate CalculatorConversion rate from conversions and visitors, with value per visitor. Sample Size CalculatorHow many survey responses you need for a given margin of error. Margin of Error CalculatorMargin of error for surveys and sample means, with finite population correction. Statistics CalculatorMean, median, mode, standard deviation, variance and quartiles of a list.