Can I test contingency tables?
This calculator handles goodness-of-fit tests. For contingency tables, flatten the observed counts and compute expected frequencies first.
Step-by-step walkthrough
Chi-Square Calculator Guide
Use this companion guide beside the interactive calculator to make sure you understand the “why” behind every click. Each section includes the classroom explanation, student-friendly language, and quick practice prompts.
Before you start
Collect the data points listed below and double-check their units. Keeping an organized “givens” list is one of the fastest ways to reduce math errors and impress exam graders.
- chi-square
- goodness of fit
- categorical
Detailed procedure
Step 1
Enter observed counts and matching expected counts.
Step 2
Ensure expected counts are positive and align with observed categories.
Step 3
Review χ², degrees of freedom, and the p-value.
Teaching & troubleshooting tips
What if expected counts are zero?
Chi-square requires all expected counts to be positive. Combine categories or use Fisher’s exact test if counts are too small.