Statistics calculator
Chi-Square Calculator
Calculate a simple chi-square statistic from observed and expected counts.
Formula
Chi-square statistic
Use a chi-square table or p-value tool for formal hypothesis testing.
chi-square = sum((observed - expected)^2 / expected)
Compare observed category counts with expected counts.
FAQs
What counts should I enter?+
Enter observed category counts and the expected counts for the same categories.
Why must expected counts be positive?+
Expected count is in the denominator, so it cannot be zero.
How does the Chi-Square Calculator calculate the result?+
It uses the Chi-square statistic: chi-square = sum((observed - expected)^2 / expected). Compare observed category counts with expected counts.
What information do I need to use the Chi-Square Calculator?+
Calculate a simple chi-square statistic from observed and expected counts.
How accurate is the Chi-Square Calculator?+
Chi-Square Calculator applies the formula and assumptions shown on this page. Results may be rounded for readability, so verify changing rates, thresholds, medical guidance, or legal rules with the cited source or a qualified professional.
What should I check before using the Chi-Square Calculator result?+
Check that the units, dates, rates, and assumptions match your situation. Change one input at a time to understand which values have the largest effect on the result.
Statistics guide
How to use the Chi-Square Calculator
Calculate a simple chi-square statistic from observed and expected counts. The page also explains the chi-square statistic and shows a practical example: Compare observed category counts with expected counts.
- 1
Enter your details
Enter observed and expected counts, then complete any other fields shown in the calculator.
- 2
Check the calculation
Review the result alongside the chi-square statistic: chi-square = sum((observed - expected)^2 / expected).
- 3
Compare scenarios
Change one or more inputs to see how they affect the chi-Square Calculator result before you use the estimate.
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