Calculator to compute the confidence interval or margin of error of a sample based on the desired confidence level. It also provides an error bar diagram.

Jul 17, 2023 · We use the following formula to calculate a confidence interval for a mean: Confidence Interval = x +/- t* (s/√n) where: Note: We replace a t critical value with a z critical value in the formula …

Mar 21, 2025 · Follow the steps below to calculate the confidence interval for your data. Write down the phenomenon you'd like to test. Let's say you're working with the following situation: The average …

The frequentist approach sees the true population mean as a fixed unknown constant, while the confidence interval is calculated using data from a random sample. Because the sample is random, …

Read Confidence Intervals to learn more. Use the Standard Deviation Calculator to calculate your sample's standard deviation and mean. Caution: you should really use the standard deviation of the …

The confidence interval calculator finds the confidence level for your data sample.

The Confidence Interval Calculator allows you to compute the confidence interval of a mean by providing the standard deviation, mean, and sample size. Alternatively, if you don’t know the aforementioned …

Free online confidence interval calculator for statistical analysis. Calculate confidence intervals for means, proportions, and more with our easy-to-use tool.

Calculate 90%, 95%, or 99% confidence intervals instantly. Input sample mean, SD, and size to get accurate bounds, margin of error, and interpretation. Perfect for researchers & students!

Jan 9, 2026 · This page explains how to create and interpret confidence intervals, using a coin flipping example. After flipping a coin 100 times, a sample proportion of 0.57 results in a 95% confidence …