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Chi-square calculator
Run a goodness-of-fit test against expected counts, or a test of independence on a contingency table of any size. Expected counts are checked automatically and flagged where the approximation becomes unreliable.
It does not say which cells drive the result, how strong the association is, or in which direction. Cramér's V gives the strength; standardised residuals show where it comes from.
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This calculator was checked by Sidra Khan, Lead Biostatistician
In short
What does a chi-square test do?
A chi-square test compares observed frequencies against the frequencies expected under a null hypothesis. A goodness-of-fit test compares one categorical variable against expected proportions; a test of independence examines whether two categorical variables are associated. It requires expected counts of roughly 5 or more in each cell.
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