TimelyScholarFree Tools › Mann-Whitney U Test Calculator
Compare two independent groups without assuming normality. Get U, an exact or tie-corrected p-value and the rank-biserial correlation.
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| U (group 1) | 105.0U for group 2 = 51.0 |
|---|---|
| p-value (two-sided) | 0.149Method: normal approximation (tie- and continuity-corrected) |
| Rank-biserial correlation | 0.346Effect size; positive means group 1 tends to be higher |
| Medians | 9.00 vs 7.00 |
| Sample sizes | 12 and 13 |
Paste the values for the first group.
Paste the values for the second group.
U, the p-value, the method used and the effect size.
The Mann-Whitney U test (also called the Wilcoxon rank-sum test) compares two independent groups using ranks rather than raw values, so it suits skewed or ordinal data and small samples.
For small samples without tied values the calculator uses the exact distribution of U; otherwise it uses the normal approximation with tie and continuity corrections.
Yes. They are equivalent tests; U and the rank-sum statistic differ only by a constant.
Not strictly. It tests whether values in one group tend to be larger than in the other; this equals a median comparison only when the distributions have the same shape.