Relative Risk Calculator
Calculate the relative risk (risk ratio) between an exposed group and an unexposed (control) group based on event counts and group totals.
What is relative risk?
Relative risk (RR), or risk ratio, compares the probability of an event occurring in an exposed group versus an unexposed (or control) group. It’s widely used in epidemiology and general risk analysis to describe how much more (or less) likely an outcome is with a given exposure.
The formula
RR = (Events in Exposed / Total Exposed) / (Events in Unexposed / Total Unexposed). An RR of 1 means no difference in risk between groups, RR greater than 1 means increased risk in the exposed group, and RR less than 1 means decreased risk.
This calculator is for general educational and statistical planning purposes and does not replace a full epidemiological study or professional risk assessment.