Statistics Calculators

Two-Sample T-Test Calculator

Calculate the t-statistic and degrees of freedom for an independent two-sample t-test (Welch's t-test) from each sample's mean, standard deviation and size.

t-statistic —

Standard error of the difference —

Degrees of freedom (Welch) —

About the Two-Sample T-Test Calculator

The independent two-sample t-test compares the means of two groups to see whether their difference is statistically meaningful. This calculator uses Welch's t-test, which does not assume the two groups have equal variances.

Formula: t = (x̄₁ − x̄₂) ÷ √(s₁²/n₁ + s₂²/n₂), with degrees of freedom from the Welch–Satterthwaite equation

Compare the resulting t-statistic against a critical value (see the critical value calculator) for the computed degrees of freedom to decide whether to reject the null hypothesis of equal means.