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Sample Size Calculator

Find how many responses you need for statistically reliable survey results.

How to use

  1. Enter your values in the fields above.
  2. Press Calculate to see your result instantly.
  3. Use the Share button to copy a link to your result.

About this calculator

This calculator finds the survey sample size needed for statistically reliable results, using the standard formula built from your desired confidence level (like 95%), margin of error (like ±5%), and population size, based on the normal distribution's z-score.

Market researchers, academic survey designers, and UX researchers use it before launching a survey to know how many respondents to target — too few and the results aren't trustworthy, too many wastes time and budget collecting data you didn't need.

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