Kruskal-Wallis H Test Calculator
Compare three or more independent groups on an ordinal or non-normal outcome, then locate differences with Bonferroni-adjusted Dunn tests.
Updated · By Bibin XavierData 90 × 12
| IDtext · 90 levels | Grouptext · 3 levels | Gendertext · 2 levels | Agenumeric | Hours_Studynumeric | Anxietynumeric | Motivationnumeric | Pre_Scorenumeric | Post_Scorenumeric | Exam_Scorenumeric | Passednumeric · coded | Satisfactionnumeric · coded |
|---|---|---|---|---|---|---|---|---|---|---|---|
| S001 | Control | Male | 23 | 11.2 | 29 | 4.6 | 60 | 62 | 67 | 1 | 2 |
| S002 | Workshop | Female | 23 | 3.9 | 28 | 3.5 | 54 | 70 | 54 | 0 | 2 |
| S003 | Online | Female | 18 | 10.1 | 32 | 4 | 55 | 57 | 66 | 0 | 3 |
| S004 | Control | Male | 26 | 13.6 | 41 | 3.5 | 52 | 55 | 59 | 0 | 3 |
| S005 | Workshop | Female | 22 | 9.7 | 27 | 3.6 | 56 | 63 | 65 | 0 | 4 |
| S006 | Online | Female | 20 | 7.9 | 32 | 3.8 | 65 | 82 | 65 | 0 | 2 |
| S007 | Control | Female | 20 | 6.3 | 28 | 3 | 72 | 83 | 61 | 0 | 3 |
| S008 | Workshop | Male | 22 | 8 | 29 | 3.1 | 64 | 72 | 62 | 1 | 3 |
Variables and options
Results
90 rows · example dataRanks
| Group | n | Median | Mean rank |
|---|---|---|---|
| Control | 30 | 3.00 | 31.23 |
| Online | 30 | 3.00 | 45.18 |
| Workshop | 30 | 4.00 | 60.08 |
Test statistics
| Kruskal-Wallis H | df | p | ε² |
|---|---|---|---|
| 20.03 | 2 | < .001 | .225 |
Note. Corrected for ties. ε² is the rank-based effect size.
Dunn’s pairwise comparisons
| Comparison | Mean rank difference | z | p | pBonf |
|---|---|---|---|---|
| Control − Online | -13.95 | -2.16 | .031 | .092 |
| Control − Workshop | -28.85 | -4.47 | < .001 | < .001 |
| Online − Workshop | -14.90 | -2.31 | .021 | .063 |
Medians by group (bars show IQR)
Interpretation
Satisfaction differed significantly across groups. Dunn tests found differences between Control and Workshop.
How to cite this tool
Using these results in a thesis, journal article, report or class assignment? Please cite this free tool so others can find it. It keeps the site free.
APA 7
Xavier, B. (2026). Kruskal-Wallis H Test Calculator [Web application]. FreeStatisticalTools.com. https://freestatisticaltools.com/kruskal-wallis-test-calculator/
BibTeX
@software{xavier_kruskalwallistest_2026,
author = {Xavier, Bibin},
title = {Kruskal-Wallis H Test Calculator},
publisher = {FreeStatisticalTools.com},
year = {2026},
url = {https://freestatisticaltools.com/kruskal-wallis-test-calculator/},
note = {Web application}
}Suggested sentence for your methods section: “The analysis was carried out with the free Kruskal-Wallis H Test Calculator tool on FreeStatisticalTools.com (Xavier, 2026).”
What is the Kruskal-Wallis test?
The Kruskal-Wallis H test compares three or more independent groups on an ordinal or non-normal outcome. It is the rank-based alternative to one-way ANOVA, followed here by Dunn’s pairwise tests.
When to use the Kruskal-Wallis test
Use it instead of one-way ANOVA for ordinal outcomes or when normality is badly violated with small groups.
Assumptions
- Independent groups.
- An ordinal or continuous outcome.
How to use this tool
- Enter your data. Paste columns from Excel, Google Sheets or SPSS with variable names in the first row, or upload a CSV or Excel file. The example data shows the expected layout.
- Choose the variables. Select the dependent variable and grouping variable.
- Read the results. Results update automatically. Read the plain-English interpretation, then use Copy table to paste APA-style tables into Word and Copy for the results sentence.
How to report the Kruskal-Wallis test in APA style
Report H, df, p and ε², then the significant Dunn comparisons.
Frequently asked questions
What post-hoc test follows Kruskal-Wallis?
Dunn’s test with a Bonferroni adjustment is the standard follow-up and is what SPSS reports for pairwise comparisons.
Does Kruskal-Wallis compare medians?
It compares rank distributions. It can be read as a test of medians only if the groups have similarly shaped distributions.
How do I report it?
Report H, degrees of freedom, p and an effect size, for example: H(2) = 9.14, p = .010, ε² = .10.
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