IC 95% Risco Relativo
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
About this calculator
The IC 95% Relative Risk Calculator is a useful tool for statisticians and researchers needing to calculate the 95% confidence interval for the relative risk (RR). Based on the formula lnRR ± 1,96·√(1/a−1/n1 + 1/c−1/n2), this calculator allows for quick and efficient calculation of the 95% IC.
When you need to know the relative risk of an event or outcome compared to a control group, this calculator is an essential tool. Moreover, IC 95% provides a measure of uncertainty for the estimated value of RR.
To use this calculator, simply insert the required values, such as the odds ratio (a), the number of observations in the exposed group (n1), the number of observations in the control group (c) and the total number of observations (n). Then, you will be able to view the calculated relative risk and 95% confidence interval.
Frequently asked questions
What is the relative risk?
The relative risk is a measure that compares the probability of an event occurring in an exposed group compared to a control group. It is an important tool in case-control studies.
What does the 95% confidence interval mean?
The 95% confidence interval provides a measure of uncertainty for the estimated value of the relative risk, indicating that the true value lies within a 95% confidence interval.
Why is it important to calculate the confidence interval?
Calculating the confidence interval helps to evaluate the precision of the estimated relative risk and to identify possible errors or bias in the data.
How can I interpret the results of the calculator?
The calculator's results provide the relative risk and 95% confidence interval. To interpret the results, you can consider whether the confidence interval includes the baseline (1), indicating that the relative risk is significantly different from the control.