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Chi-Square Test Calculator

Compute the chi-square (χ²) statistic from observed and expected frequencies to test goodness of fit or independence. Use it whenever you need to determine whether categorical data match a theoretical distribution.

Observed Frequency 1

Expected Frequency 1

Observed Frequency 2

Expected Frequency 2

Fill in the required fields to see your result.

Statistics

Chi-Square Test Calculator

Compute the chi-square test statistic contribution for one observed-vs-expected category pair using χ² = (observed − expected)² / expected. Sum these contributions across all categories to get the total χ² statistic for goodness-of-fit or independence tests.

Observed Frequency

Expected Frequency

Fill in the required fields to see your result.

Key differences

	Chi-Square Test Calculator	Chi-Square Test Calculator
Category	Statistics	Statistics
Inputs required	4	2
Result	Chi-Square Statistic	Chi-Square Value
What it does	Compute the chi-square (χ²) statistic from observed and expected frequencies to test goodness of fit or independence. Use it whenever you need to determine whether categorical data match a theoretical distribution.	Compute the chi-square test statistic contribution for one observed-vs-expected category pair using χ² = (observed − expected)² / expected. Sum these contributions across all categories to get the total χ² statistic for goodness-of-fit or independence tests.