Chi Square Calculator
Calculate the chi-square statistic for observed and expected values using a goodness-of-fit style setup.
Enter lists separated by commas, spaces, or line breaks.
χ² = Σ((O − E)² / E)
| Metric | Value |
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Privacy: calculations run locally in your browser. No inputs are stored or transmitted.
How it works
This tool compares observed counts to expected counts and sums the contribution from each category.
Degrees of freedom for a simple goodness-of-fit setup are often:
df = categories − 1
Examples
- Observed: 18, 22, 20, 25
- Expected: 21.25, 21.25, 21.25, 21.25
- Each category contributes (O − E)² / E
FAQ
- What does this chi-square calculator compute?
It computes the chi-square statistic from observed and expected category values using the goodness-of-fit formula.
- What is the chi-square formula?
Chi-square = Σ((observed − expected)² / expected).
- Why must expected values be greater than 0?
Because the formula divides by expected values, so expected values must be positive.
- Are calculations stored?
No. Everything runs locally in your browser.