The incidence rate is a measure of the frequency with which some event, such as a disease or accident, occurs over a specified time period.
Formula to calculate incidence rate.
![Calculate Incidence Rate.](https://www.learntocalculate.com/wp-content/uploads/2020/08/incidence-rate.png)
Example:
In a day, there were 40 new corona virus cases, the county’s population is 40,000 people. Calculate the incidence rate.
![Calculate Incidence Rate.](https://www.learntocalculate.com/wp-content/uploads/2020/08/incidence-rate-2.png)
Therefore, the disease’s incidence rate is 0.001.