Sample Size Calculator
Required sample size for proportion surveys with finite-population correction.
How to Use
- Pick confidence level and margin of error.
- Provide population size for finite-population correction.
Show Work
Formulas
About the Sample Size Calculator
Use the Sample Size Calculator — a free, easy tool for everyday maths and number work. Nothing is uploaded, and you do not need an account. Required sample size for proportion surveys with finite-population correction.
How it works
Put each value in its box and read the answer as you go. Because it recalculates live, you can play with the inputs to see how each one moves the result — handy for checking your own working or planning ahead. Everything happens on your device, so it is fast and private.
Want the deeper story? The Knowledge Base explains the ideas behind the tools in more detail.
Frequently Asked Questions
How do I use the Sample Size Calculator?
Simply type your numbers and read the result, which refreshes the instant you change something. There is nothing to submit and nothing to wait for.
Do I need to install or sign up for anything?
Not at all — it runs in the browser with nothing to install and no account. After it loads once, it even works without an internet connection.
Is my information private?
Yes. Everything happens in your browser. Nothing you type is sent to a server or saved anywhere.
Common Use Cases
Try different numbers
Change one thing and watch the answer change. It is an easy way to compare your choices.
Nothing to set up
Open the page and start. There is nothing to install, and no account to make.
Check your work
Worked it out yourself? Use the Sample Size Calculator to make sure your answer is right.
No data leaves your browser
The tool runs locally, so whatever you enter stays with you and only you.
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