McNemar's Test Calculator
Test the significance of changes in paired dichotomous data
Enter the counts for a 2x2 contingency table of paired observations.
After: Positive
After: Negative
Before: Positive
Before: Negative
About McNemar's Test
McNemar's test is used for paired nominal data in a 2x2 table.
It tests whether the row and column marginal frequencies are equal (symmetry).
Formula: χ² = (|b - c| - 1)² / (b + c)
The test focuses only on discordant pairs (cells b and c).