If you think that our site could be of use to your website's visitors you can link to our site

# Odds Ratio Calculator

Instructions: This calculator computes the Odds Ratio (OR) for a 2x2 crosstabulation, which measures the ratio of the odds of exhibiting a condition (or disease) for those in an exposed group, versus the the odds of exhibiting the condition (or disease) for those in the non-exposed group. Please type the 2x2 table data and also indicate the confidence level required to compute the confidence interval for the odds ratio (OR)

Type the values of the 2x2 table:

Disease
No Disease
Exposed
Not Exposed

Confidence Level = (Ex: 0.99, 0.95, or 99, 95 without "%", etc)

More about the Odds Ratio (OR)

The odds ratio (OR) corresponds to ratio of the odds of having a condition for those exposed to a certain treatment, versus the the odds of having a condition for those not exposed to the treatment.

Let us consider the folllowing 2x2 crosstabulation:

Disease
No Disease
Exposed
$$a$$
$$b$$
Not Exposed
$$c$$
$$d$$

The Odds Ratio of having the condition for those in the exposed group respect to the non-exposed group is computed using the following formula:

$OR = \frac{a/b}{c/d}$

### Get solved Math Problems, Math Cracks, Tips and Tutorials delivered weekly to your inbox

* indicates required