What is the 2×2 Chi-Square Calculator?
Calculate Pearson’s chi-square statistic for a 2×2 contingency table. ITS Research Solution keeps the interactive tool above the explanation so you can calculate first and then review the method used.
Formula or method
χ² = Σ (observed−expected)² / expected.
How to use this tool
Enter the requested values using consistent units, run the calculation and review the main result plus any supporting values. Enter four cell counts to calculate χ² with 1 degree of freedom.
Interpretation and limitations
For sparse tables or very small expected counts, an exact method may be more appropriate. Always check source data, units, rounding and discipline-specific requirements before using a result in assessed, published, regulated or high-stakes work.
Frequently asked questions
How is this result calculated?
u03c7u00b2 = u03a3 (observedu2212expected)u00b2 / expected.
Can I use this result in formal academic or research work?
Use it as a transparent calculation aid, then verify the assumptions, units, rounding and any institution-, journal- or field-specific requirements before formal use.