About This Tool

Our confidence interval calculator helps you determine the range within which a population parameter (such as the mean or proportion) is likely to fall. Confidence intervals are a key concept in statistics, providing a measure of the uncertainty associated with your sample data.

Enter your sample statistics and select your desired confidence level to calculate the interval.

What is a Confidence Interval?

A confidence interval is a range of values, derived from sample statistics, that is likely to contain the value of an unknown population parameter. The confidence level (e.g., 95%) represents the proportion of intervals that would contain the true parameter if you were to take many samples.

For example, a 95% confidence interval means that if we were to take 100 different samples and compute a 95% confidence interval for each sample, then approximately 95 of the 100 confidence intervals will contain the true population parameter.

Formulas Used