About Confidence Interval
Confidence Interval is a free, fast and reliable online tool. Calculate a 95% confidence interval. You can configure Mean, Standard deviation and Sample size to get the result. Everything runs locally in your browser — no files are uploaded and no data is stored, keeping your information completely private. It works responsively on both desktop and mobile devices.
How to use Confidence Interval
- 1 Enter Mean, Standard deviation and Sample size
- 2 Click "Convert"
- 3 Review the result and click "Copy"
Frequently asked questions
How do I use Confidence Interval?
Enter Mean, Standard deviation and Sample size and the result is calculated instantly in your browser.
Is Confidence Interval free to use?
Yes — Confidence Interval is a free online tool. No sign-up or login is required, and there are no hidden charges or usage limits.
Do I need to create an account to use Confidence Interval?
No. Confidence Interval runs entirely online in your browser — there is no account to create, no login, and nothing to install.
Does Confidence Interval upload my data?
No. Everything runs locally in your browser. Your input never leaves your device, is never stored, and is never tracked, so it stays private.
Free, online, and private
Free to use
Confidence Interval is completely free. There is no account to create, no login, and no hidden charge or usage limit.
Runs online in your browser
It is a free online tool that runs entirely in your browser. Nothing to download or install — open the page and start using it right away.
Your data stays private
All processing happens locally on your device. Your input is never uploaded, stored, or tracked, so it never leaves your browser.