Chi square calculator

Chi-square test calculator
CategoryObserved frequencyExpected frequency

Calculate chi-square statistics online with ease

Perform chi-square tests for goodness of fit and independence with our easy-to-use calculator. Get instant results including chi-square statistic, degrees of freedom, p-value, and visualize the chi-square distribution.

Support for both goodness of fit and independence tests

Calculate chi-square statistic and p-value

Interactive chi-square distribution visualization

Dynamic data input for multiple categories

Start free - no email address needed

Perfect for hypothesis testing

How to use the chi-square calculator online

  1. Select test type
    Choose between Goodness of Fit test or Independence test
  2. Enter your data
    Input your observed and expected frequencies
  3. Calculate results
    Click calculate to get the chi-square statistic and p-value
  4. Interpret results
    Use the p-value to determine statistical significance and view the distribution visualization

Example chi-square test scenarios

Goodness of Fit Test Example

Testing if observed frequencies match expected frequencies in a dice roll experiment:

Sample Data:

Observed Frequencies:
  • Face 1: 158
  • Face 2: 172
  • Face 3: 164
  • Face 4: 181
  • Face 5: 160
  • Face 6: 165
Expected Frequencies:
  • Face 1: 166.67
  • Face 2: 166.67
  • Face 3: 166.67
  • Face 4: 166.67
  • Face 5: 166.67
  • Face 6: 166.67

Results:

  • Chi-square statistic: 2.47
  • Degrees of freedom: 5
  • P-value: 0.781
  • Interpretation: Since p-value > 0.05, we fail to reject the null hypothesis that the dice is fair

Independence Test Example

Testing if there's an association between gender and course selection:

Sample Data:

Observed Frequencies:
  • Science (M): 120
  • Science (F): 80
  • Arts (M): 60
  • Arts (F): 140
Expected Frequencies:
  • Science (M): 90
  • Science (F): 110
  • Arts (M): 90
  • Arts (F): 110

Results:

  • Chi-square statistic: 47.52
  • Degrees of freedom: 1
  • P-value: < 0.0001
  • Interpretation: Since p-value < 0.05, we reject the null hypothesis of independence, suggesting there is an association between gender and course selection