Statistics

Sample Size Calculator

How many survey responses do you actually need? This tool calculates the minimum sample size for estimating a population proportion, accounting for margin of error, confidence level, and population size. Uses the conservative p = 0.5 assumption.

Margin of Error (±)

Typical values: 1% = 0.01, 3% = 0.03, 5% = 0.05

Confidence Level

Population Size (leave blank or 0 for large/unknown)

Use finite population correction if population is small and known

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minimum sample size required

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Margin of Error

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Confidence

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Population

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Infinite-pop n