95% Confidence Interval Calculator - Free, Instant, In Your Browser
Enter the sample mean, standard deviation, and sample size to calculate the 95% confidence interval.
How to use Confidence Interval 95 Calculator
- 1Enter the required date(s) and details above.
- 2Click Calculate - Confidence Interval 95 Calculator runs instantly, right in your browser.
- 3Read your result below.
Your file is processed in your browser and is never uploaded.
Frequently Asked Questions
What's the formula?
CI = mean ± 1.96 x (standard deviation / √(sample size)), using the standard z-value for a 95% confidence level.
Is my data sent to a server?
No - everything runs entirely in your browser with JavaScript. Nothing is uploaded.