Mann-Whitney U Test Calculator

This calculator performs the Mann-Whitney U test (also called Wilcoxon rank-sum test), a non-parametric alternative to the independent samples t-test. Use this when your data doesn't meet the normality assumption.

Go to Calculator →

When to Use

  • Comparing two independent groups
  • Data is ordinal or continuous but not normally distributed
  • Sample sizes are small
  • Outliers are present that would skew parametric tests

Advantages

  • No assumption of normal distribution
  • Robust to outliers
  • Can be used with ordinal data

Null Hypothesis

H₀: The distributions of both groups are equal (or equivalently, the probability that a randomly chosen value from one group is greater than a randomly chosen value from the other group equals 0.5)

Calculate Mann-Whitney U