Chi-Square Goodness of Fit
Compare observed category counts with positive expected counts.
Your numbers
Chi-square statistic
Use consistent units. The result follows the assumptions you enter.
Scenario comparison
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Formula
Use χ² = Σ(Oᵢ−Eᵢ)²/Eᵢ and df = k−1−p. Oᵢ and Eᵢ are observed and expected counts, k is category count, and p is parameters estimated from the same data. The p-value is the upper chi-square tail.
Compare observed category counts with positive expected counts.
Worked example
- Observed counts
- 10, 20, 30
- Expected counts
- 20, 20, 20
- Parameters estimated from the same data
- 0
- Chi-square statistic
- 10
- Degrees of freedom
- 2
- p-value
- 0.00673794699909
Scope and limitations
Use consistent units. The result follows the assumptions you enter.
Inputs are checked for missing values and allowed ranges. A result outside the finite numeric range is not displayed. Rounding affects display, while the calculation uses the model’s numeric precision.
Check your units and assumptions before relying on a result. Changing a label does not convert a currency or physical unit.
Formula version: b6c7ff36547c · Example checked: