Confidence Interval Calculator
Calculate the confidence interval for a sample mean.
Result
Results are estimates for general information only and are not professional advice.
Confidence intervals
A confidence interval gives a range that likely contains the true population mean. Using the mean, standard deviation, sample size and confidence level, this calculator finds the margin of error and the interval bounds.
Frequently Asked Questions
What is the Confidence Interval Calculator?
Calculate the confidence interval for a sample mean. It runs instantly in your browser and is completely free to use.
What do I need to enter to use the Confidence Interval Calculator?
The Confidence Interval Calculator asks for the following values (4): Sample mean, Standard deviation, Sample size, Confidence level. Fill them in and the result appears immediately — the calculation runs on your own device, so nothing you type is sent to a server.
How accurate is the Confidence Interval Calculator?
The Confidence Interval Calculator uses standard, widely-accepted formulas, so its figures are reliable estimates for everyday planning. They are not a substitute for advice from a qualified professional.
Is the Confidence Interval Calculator free, and do I need an account?
Yes. The Confidence Interval Calculator — and every other calculator on Calculatis — is completely free, with no registration, no download and no limit on how often you use it.