Sample Size Calculator

Required sample size for proportion surveys with finite-population correction.

Calculator Numbers & Math Updated Apr 20, 2026
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How to Use
  1. Pick confidence level and margin of error.
  2. Provide population size for finite-population correction.
Input
Required sample

Formulas

Infinite population
n₀ = z² · p(1−p) / E²
Finite population
n = n₀ / (1 + (n₀ − 1)/N)

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