Phi Coefficient Calculator

Calculate the correlation between two binary variables

Enter the counts for a 2x2 contingency table.

Variable 2: Yes

Variable 2: No

Variable 1: Yes

Variable 1: No

Phi (φ) measures association between two binary variables.

Formula: φ = (ad - bc) / √(r1 × r2 × c1 × c2)

Range: -1 to +1 (like Pearson's r)

Relationship: χ² = φ² × n