What this calculator does
Chi-square goodness of fit works out tests whether observed category counts match expected counts. Enter your own figures above and the answer updates as you type: nothing is fixed in the code, so the result reflects exactly the numbers you supply.
The formula this calculator evaluates is printed under the tool and explained below, so you can check the working by hand or reuse it in a spreadsheet.
The formula
Formulaχ² = Σ (Oᵢ − Eᵢ)² / Eᵢ; degrees of freedom = number of categories − 1
The inputs explained
| Field | What to enter |
|---|---|
| Observed counts (comma separated) | A list of numbers, separated by commas or spaces. |
| Expected counts (comma separated) | A list of numbers, separated by commas or spaces. |