Finite-population proportion planning
Calculate a simple random sample size with finite-population correction.
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Population must be an integer ≥2. Proportion is strictly inside 0–1, margin inside 0–0.5, confidence 0.8–0.999. Margin is absolute, not relative.
The starting values are hypothetical. Results update as you edit. Use aggregate or synthetic inputs only.
Calculation results
- Infinite-population approximation
- 384.14588
- Finite-population unrounded n
- 277.73345
- Completed responses required
- 278
How to interpret the output
Normal-approximation n0=z²p(1−p)/margin² is adjusted to n=n0/[1+(n0−1)/N] and rounded upward. Assumes simple random sampling without replacement from a complete finite population. Nonresponse, clustering, weights and rare events require additional planning; the nominal margin is approximate.
Method referenceSource checked 2026-11-06. Read the reproducible calculator validation report.