Free · Math · Statistics & Probability

Sample Size Calculator

Estimate a survey sample size from confidence level, margin of error, population, and expected proportion.

  • Calculation method included
  • Private in your browser
  • No signup
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Calculator inputs

Enter your values

Result

Your calculation

Recommended sample
383 people
Unlimited-population sample
385 people
Finite population correction
0.3817%

This standard proportion estimate assumes a simple random sample and independent responses.

How to use this calculator

  1. Enter the known values using the units shown.
  2. Choose the calculation you want when more than one method is available.
  3. Calculate, then review the result and the worked formula together.

Private by default

Inputs and results stay in this browser tab. Bookify does not upload or store the values you enter.

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