How it works
Fill in the 2 fields above and Sample Size Calculator calculates the result instantly, recalculating as you change any value. The math runs locally in your browser — nothing is sent to a server.
Examples
- Margin of error 5 % → Sample size: 385
Frequently asked questions
How do I use the Sample Size Calculator?
Enter your values in the 2 input fields and the result is calculated automatically as you type. Change any value to see the numbers update instantly.
Is my data private?
Yes. The Sample Size Calculator runs entirely in your browser. Nothing you enter is uploaded, saved to a server, or shared — it never leaves your device.
Is the Sample Size Calculator free?
Yes, it is completely free with no sign-up, no limits and no watermarks. Like every tool on statistics and the rest of the platform, you can use it as often as you like.
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