# McNemar’s Test Calculator

Instructions: Use this McNemar test calculator calculator to compute the results of applying McNemar's procedure to paired nominal data, in order to assess the level of association between the paired responses, using the form below:

Yes (Post)
No (Post)
Yes (Pre)
No (Pre)
Significance level $$(\alpha)$$ =

McNemar's Test corresponds to a test used to test the association between nominal variables, for the case when the nominal data are paired.

### How do you compute McNemar's test statistic?

Let us consider the following 2x2 crosstabulation:

Yes (Post)
No (Post)
Yes (Pre)
$$a$$
$$b$$
No (Pre)
$$c$$
$$d$$

The test statistics for McNemar's test is:

$\chi^2 = \frac{(b-c)^2}{b+c}$

where the test statistic has a Chi-Square distribution with $$df = 1$$ degree of freedom. If the nominal variables you are analyzing are not paired, the you should use a Chi-Square test for independence instead.

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