What is the Chi-Square Calculator?

The Chi-Square Calculator is a statistical tool used to determine how well observed data fit expected frequencies, often applied in tests of independence or goodness-of-fit. By entering observed and expected frequencies, this calculator computes the Chi-Square (χ²) statistic, which helps you decide whether deviations from expected values are due to chance or indicate a significant difference. This is especially useful for students, researchers, and analysts in fields like social sciences, biology, or quality control.

How to Use:

1. Enter Observed Frequencies: Input your data as comma-separated numbers representing observed counts.
2. Enter Expected Frequencies: Input the corresponding expected counts in the same order and length as observed frequencies.
3. Click “Calculate”: The calculator computes the χ² statistic using the formula χ² = Σ((Oᵢ – Eᵢ)² / Eᵢ), where Oᵢ and Eᵢ are observed and expected values.
4. Review the Result: The resulting χ² value can be compared with a critical value from Chi-Square distribution tables to test hypotheses.