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McNemar's Test χ² from a Paired 2×2 Table Calculator

χ² = (b − c)² / (b + c); Yates: (|b − c| − 1)² / (b + c).

Compute McNemar's chi-square statistic for paired-categorical data (e.g. yes/no before vs after a treatment in the same subjects). Uses only the off-diagonal counts b and c. χ² = (b − c)² / (b + c) tested with df = 1; Yates' continuity correction (|b − c| − 1)² / (b + c) for small counts.

Daniel Oh By Daniel Oh
Published Last reviewed 1 min read

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Formula

χ² = (b − c)² / (b + c).

In depth

Compute McNemar's chi-square statistic for paired-categorical data (e.g. yes/no before vs after a treatment in the same subjects). Uses only the off-diagonal counts b and c. χ² = (b − c)² / (b + c) tested with df = 1; Yates' continuity correction (|b − c| − 1)² / (b + c) for small counts.