Created By : Vaibhavi Kumari
Reviewed By : Phani Ponnapalli
Last Updated : Apr 02, 2023

Relative Risk Calculator helps you find the comparitive risk occurence of a significant event for two groups. This calculator can be of great help in your statistical calculations and all you need to do is provide the respective inputs and tap on the calculate button to get risk or confidence interval.

Exposed Group
Disease
No Disease
Control Group
Disease
No Disease
Relative Risk

### What is Relative Risk or Risk Ratio?

Relative Risk or Risk Ratio of something is when you compare the odds of two groups against each other. In other words, we can put it as the relative difference in risk between exposed group and a control group.

## Relative Risk Formula

Risk Ratio Formula OR relative risk equation is the ratio between control group and exposed group. The formula looks as such RR = [a / (a + b)] / [c / (c + d)]

• where: a is the number of members of exposed group who developed the disease
• b is the number of members of exposed group who didn't develop the disease
• c is the number of members of control group who developed the disease
• d is the number of members of control group who didn't develop the disease
• RR is the relative risk

Once you find the relative risk you might probably search for what the result means. Refer to the guidelines below

• If the risk ratio is equal to 1 it means there is no much difference between the two groups.
• If the relative risk is lower than 1 it means the risk is lower in the exposed group.
• If the risk ratio is higher than 1 then it means risk is high in case of exposed group.

Understand the difficult concepts too easily taking the help of the online tools available at Probabilitycalculator.guru and clarify your doubts during homework or assignments.

### How to Calculate Relative Risk and Confidence Interval?

Calculating relative risk, Now that you are aware of relative risk formula you can simply substitute the known values and simplify to get the relative risk value. To check whether the risk ratio value obtained is correct or not it entirely depends on the confidence level. Confidence Level can be used to tell how sure the result lies within a particular range also known as confidence interval.

Confidence Interval can be found using the following formulas

• lower bound = exp[ ln(RR) - Zc * √(1/a + 1/c - 1/(a + b) - 1/(c + d))]
• upper bound = exp[ ln(RR) + Zc * √(1/a + 1/c - 1/(a + b) - 1/(c + d))]

Where Zc is the Z-Score corresponding to confidence level chosen.

### FAQs on Risk Ratio Calculator

1. What is Relative Risk?

Relative Risk or Risk Ratio is where you compare the odds for two groups against each other.

2. What is Risk Ratio Formula?

Risk Ratio Formula is given by the expression RR = [a / (a + b)] / [c / (c + d)].

3. What does a Relative Risk of 2.0 mean?

Relative Risk of 2 means that people would be twice as likely to contract the disease from the exposed group.

4. How do you use the Relative Risk Calculator?

You can use the Relative Risk Calculator by simply providing the inputs in the input boxes allotted and clicking on the calculate button to avail the risk ratio in a fraction of seconds.