0 respondents needed
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Unlimited population
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Adjusted for population
Uses Cochran’s formula n₀ = z²·p·(1−p) ÷ e², with a finite-population correction when a population size is given. Use 50% response distribution for the most conservative (largest) sample.
Frequently Asked Questions
How is sample size calculated?
We use Cochran’s formula: n₀ = z² × p × (1−p) ÷ e², where z is the confidence z-score, p is the expected proportion and e is the margin of error. For a known population we apply a finite-population correction.
Find the survey sample size you need for a chosen confidence level and margin of error.