Chi-Square Calculator - Calculator See


Chi-Square Calculator

Calculate Pearson's Chi-Square statistic (chi^2), degrees of freedom, and p-value for contingency tables and goodness-of-fit tests.

Calculator Inputs

Comma-separated observed counts.
Comma-separated expected counts.

Calculated Results

Chi-Square Statistic (chi^2)
6.400 (p = 0.0408)
Degrees of Freedom (df) 2
P-Value 0.0408
Significance at alpha = 0.05 Statistically Significant
Values calculate live as you adjust inputs.

About Chi-Square Calculator

Tests whether observed categorical frequencies differ significantly from expected theoretical frequencies.

What is Chi-Square Calculator?

Tests whether observed categorical frequencies differ significantly from expected theoretical frequencies.

How to Use This Calculator

  1. Enter comma-separated observed frequency counts.
  2. Enter corresponding expected frequency counts.
  3. Review chi-square test statistic and p-value.

The Mathematical Formula & Variables

Chi^2 = sum((Observed - Expected)^2 / Expected)

Step-by-Step Worked Example

Scenario: Observed: [25, 45, 30], Expected: [33.33, 33.33, 33.33].

  1. (25 - 33.33)^2 / 33.33 = 2.08.
  2. (45 - 33.33)^2 / 33.33 = 4.08.
  3. (30 - 33.33)^2 / 33.33 = 0.33.
  4. Sum chi^2 = 2.08 + 4.08 + 0.33 = 6.49.

Result: Chi^2 = 6.400

Frequently Asked Questions

What is the minimum expected count per cell?

As a rule of thumb, chi-square tests require expected cell frequencies to be at least 5 for asymptotic normality.