Statistics calculator

Chi Square Calculator

Run a goodness-of-fit calculation, analyze a contingency table, or convert a chi-square statistic to its right-tail p-value.

Enter values

Enter values and select Calculate.

Formula and methodology

Goodness of fit sums (O−E)²/E with df = k−1. Independence calculates expected cells from row and column totals with df = (r−1)(c−1). Right-tail p-values use the regularized upper incomplete gamma function Q(df/2, χ²/2).

Worked example

Observed 10, 20, 30 against expected 15, 15, 30 gives χ² = 3.333333, df = 2, and p ≈ 0.188876.

Assumptions and interpretation

  • Datasets and results stay in this browser and are not sent to analytics.
  • This educational tool performs mathematical computation; it does not establish causation, choose a study design, or validate scientific conclusions.
  • Check assumptions, sampling methods, and context before interpreting an inferential result.
  • Keep full precision for decisions; displayed values are rounded for readability.