Sample
Size
Calculator

Calculate the required sample size for surveys and experiments using Cochran's formula with finite population correction.

Input

Leave blank for infinite population

Confidence Level

Use 50% if unsure (maximizes sample size)

Result

Required Sample Size

385

Margin of Error

±4.99%

Confidence Level

95%

Proportion

50%

Common Sample Sizes

5% Margin · 50% Proportion
Population90% CL95% CL99% CL
500176218286
1,000214278400
5,000257357586
10,000264370623
50,000270382655
100,000270383660
1,000,000271385664
Infinite271385664