Sample Size Calculator

%
%

Use 50% if unsure; it gives the largest, safest sample.

Leave 0 for a very large or unknown population.

Sample size needed

385

Unrounded size
384.15
Size for an unlimited population
385
Z critical value
1.96
Finite population correction
Not applied
At a 30% response rate, invite
1,284

Open the full sample size calculator with the formula and FAQs at Calcs for Life