Sample Size Calculator
Sample Type
For Proportions
Pass/fail, defect rates, yes/no surveys
For Means
Measurements, weights, dimensions
Confidence Level
80%
85%
90%
95%
99%
99.9%
Margin of Error (%)
Expected Proportion (%)
Use 50% if unknown (maximizes sample size)
Population Size (optional — leave 0 for infinite)
Calculate Sample Size
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ReliabilityCalc