Free Proportion Sample Size Calculator - This calculator determines a sample size to select to meet certain criteria related to a confidence percentage, reliability percentage, and a p value proportion. Simply enter your values not using percentage signs. This works whether p^ is known or not known.

This calculator has 4 inputs.

This calculator has 4 inputs.

p = n/N

α = 1 - Confidence%

Sample Size = Z-score^{2} x p x (1 - p)/SE^{2}

For more math formulas, check out our Formula Dossier

α = 1 - Confidence%

Sample Size = Z-score

For more math formulas, check out our Formula Dossier

- proportion
- n equation in which two ratios are set equal to each other

a/b = c/d - proportion sample size
- reliability
- the overall consistency of a measure
- sample size
- measures the number of individual samples measured or observations used in a survey or experiment.