What is this calculator?
Estimate the sample size for a population proportion.
What can you use it for?
Use it when solving an exercise, checking a result, or working with the particular quantities shown in this form. Estimate the sample size for a population proportion.
How to use it
- Enter critical z value.
- Enter expected proportion (0–1).
- Enter margin of error (0–1).
- Select Calculate (or Generate for random tools).
- Read the answer and any additional results below the form. Check the units and the limits of the method.
Formula and method
The formula uses the units and definitions shown above. Each input is substituted before the arithmetic is evaluated; the calculated output is rounded for display.
Worked example
Critical z value: 1.96, Expected proportion (0–1): 0.5, Margin of error (0–1): 0.05. The result is 385 (result).
Assumptions and limits
Simple random sample and normal approximation. No finite-population correction.
Frequently asked questions
What inputs does the Sample Size Calculator need?
Use critical z value, expected proportion (0–1), margin of error (0–1). Read the answer and any additional results below the form. Check the units and the limits of the method.
What assumptions apply to the Sample Size Calculator?
Simple random sample and normal approximation. No finite-population correction.