Sample Size Calculator for Surveys

Enter margin of error, confidence level, expected proportion and (optional) population size.

Examples

Why include population?

Applies the finite population correction, reducing required n.

Calculate permutations P(n,r) — arrangements where order matters.

Calculate combinations C(n,r) — selections where order does not matter.

Compute mean, median, mode, standard deviation, variance, min, max and more.

Convert a value to a standard score (z) and approximate percentile.

Calculate probability percentage and odds from favorable and total outcomes.