Sample Size Calculator

Calculate required sample size for surveys and research.

Formula: n = (Z^2 * p * (1-p)) / E^2

Use 50% for maximum sample size if unsure

Quick Reference - Sample Sizes (95% confidence, 50% proportion)

Margin of Error 1% 3% 5% 7% 10%
Sample Size 9,604 1,067 385 196 96

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