One-Sample T-Test Calculator

About this calculator

This calculator computes the one-sample t-statistic, t = (x̄ − μ) / (s / √n), which measures how many standard errors your sample mean x̄ sits away from a hypothesized population value μ, using the sample standard deviation s and sample size n. The result is compared against a t-distribution with n − 1 degrees of freedom to get a p-value, since with small samples the t-distribution's fatter tails account for the extra uncertainty of estimating the standard deviation from the data itself.

Researchers use it whenever they want to check a sample against a known or claimed benchmark — a factory testing whether a batch's average weight matches its printed specification, or a researcher checking whether a class's test scores differ from a national average — without needing a second comparison group.