Quick guide
How to use this calculator
- Enter the observations, probabilities, model parameters, or summary statistics requested by the visible labels.
- Keep every value on the same scale and confirm that the selected sampling relationship, distribution, and tail convention match the question you are investigating.
- Read the result together with its assumptions and interpretation. Statistical output summarizes uncertainty under a model; it does not repair biased data or establish causation.
Calculation method
How the mann–whitney u test calculator works
U derives from each group’s rank sum; variance is corrected for tied ranks.
The test targets stochastic distribution differences; a pure median interpretation needs similarly shaped distributions.
Worked example
Mann–Whitney U Test example
Samples 1, 2, 3 and 4, 5, 6 have complete rank separation and U=0 for the first group.
U derives from each group’s rank sum; variance is corrected for tied ranks.
Supported inputs
Precision and limits
Model and design
Samples and observations must be independent and at least ordinal; this route consolidates the Wilcoxon rank-sum synonym.
Numerical scope
Inputs use double-precision numerical methods with guarded domains. Datasets accept up to 10,000 finite plain-decimal values. Extremely large parameters or probabilities deep in a numerical tail may require specialist statistical software.
Interpretation
The test targets stochastic distribution differences; a pure median interpretation needs similarly shaped distributions.
Decision boundary
The calculator does not validate how data were collected, diagnose dependence or bias, choose a scientifically meaningful effect, or replace review by a qualified statistician for consequential research, medical, regulatory, safety, or policy decisions.
Privacy
Entered values and calculated results stay in this browser and are not sent to an analytics service.
Continue calculating