t-Statistic and Degrees of Freedom Calculator

The test statistic for a Student t-test hypothesis test is called a t-statistic. The t-statistic is used to measure how extreme an estimate is. The formula used to calculate t-statistic is the following: $$ t = \frac{x - \mu}{s / \sqrt{n}} $$ Where \(x\) is the mean, \(\mu\) is the hypothesized mean (in many situations, the hypothesized value is 0), \(s\) is the standard deviation and \(n\) is the sample size. Degrees of freedom determines how much a final calculation of a statistic is free to vary. The formula used to calculate it is the following: $$ df = n - 1 $$ Use the calculator below to solve your t-statistic problems.