Relative Risk Calculator
Enter four nonnegative integer counts for exposed and unexposed groups.
RR = (a/(a+b)) ÷ (c/(c+d)).
This is a point estimate of association, not causation. No confidence interval or p value is calculated.
A QUICK WALKTHROUGH
How to use this tool
- Enter the four counts for exposed outcomes and non-outcomes and unexposed outcomes and non-outcomes.
- Calculate the exposed risk divided by the unexposed risk.
- Review the point estimate and its interpretation limits.
Formula
RR = (a/(a+b)) / (c/(c+d)), where a and b are exposed outcomes and non-outcomes, and c and d are unexposed outcomes and non-outcomes.
Interpretation
Relative risk describes an association in this table; association is not causation. This tool reports a point estimate only, without confidence intervals or p values.
Local processing
Inputs and arithmetic stay in this browser.
GOOD TO KNOW
Common questions
What groups does this use?
The table compares exposed and unexposed groups. Each group total must be positive, and the unexposed reference risk must be nonzero.
Does relative risk prove causation?
No. An association is not causation.