Chi-square test calculator
Choose a calculation. Expected counts and each category or cell contribution are shown.
Contributions to the statistic
| Category / cell | O | E | (O−E)²/E |
|---|---|---|---|
| Fill in the fields above — the result is computed on this page. | |||
How do I use this page?
- Choose a mode.
- Enter counts.
- Read chi-square, df and p.
What this page does not do: The usual approximation can be unreliable with small expected counts or dependent observations.
Further reading
Theory — what is the chi-square test?
The chi-square test compares observed counts with expected counts. In an independence table, expected counts come from multiplying the row sum by the column sum and dividing by the overall total. The calculator shows these expected values together with each category or cell contribution to the test statistic. Values must be entered as observation counts, since the test does not accept percentages.
Frequently asked questions
Can I enter percentages?
See also
A/B test calculator
Compare two proportions in an A/B test. Calculate conversion rates, difference, uplift, z score, p value and c
A/B test planning — sample size, MDE and duration
Plan a two-proportion experiment, estimate detectable effect and traffic duration.
ACF and PACF autocorrelation calculator
Calculate ACF and PACF across time-series lags. Review the chart, reference bounds and coefficient table.