Mann Whitney U-test Calculator
The Mann–Whitney U test (Wilcoxon rank-sum test) is a nonparametric comparison of two independent samples based on ranks. Use this calculator to obtain a critical U value for your sample sizes when assessing whether one group tends to produce larger values than the other.
Use this free calculator to compute a Mann-Whitney critical U value. Please input comma separated sets of values in SAMPLE 1 and SAMPLE 2 in the required fields and click CALCULATE.Frequently asked questions
When is Mann–Whitney used instead of a t-test?
When you prefer a rank-based test or doubt normality, especially with ordinal data or skewed continuous data.
What does the null hypothesis usually state?
That the two distributions are the same (often framed as equal medians under extra assumptions), or that P(X greater than Y) equals P(X less than Y).
Are the samples required to be paired?
No. Mann–Whitney assumes two independent samples; use a signed-rank test for paired data.
What is a critical U value?
A cutoff for the U statistic at a chosen significance level and pair of sample sizes.