Chi-Square Calculator

Calculate chi-square statistic, p-value, and test for goodness of fit or independence

Data Input

Results

What is Chi-Square Test?

The Chi-Square test is a statistical method used to determine if there is a significant association between categorical variables or if observed frequencies differ significantly from expected frequencies. It's commonly used for goodness of fit tests and tests of independence.

Chi-Square Formula

The chi-square statistic is calculated as:

χ² = Σ[(O - E)² / E]

Where:

  • O = Observed frequency
  • E = Expected frequency
  • Σ = Sum over all categories

How to Use the Calculator

  1. Enter observed frequencies
  2. Enter expected frequencies
  3. Click "Calculate" to get the chi-square statistic
  4. View the results and interpret

Applications

  • Goodness of Fit: Test if data follows expected distribution
  • Independence Test: Test if variables are independent
  • Contingency Tables: Analyze categorical data relationships
  • Quality Control: Test if defects follow expected pattern
  • Survey Analysis: Test response patterns