Enter the total number of injuries and the total employee hours worked into the calculator to determine the injury rate.

Injury Rate Formula

The following formula is used to calculate an injury rate:

IR = (I * 200,000) / EHW
  • Where IR is the injury rate
  • I is the number of injuries
  • EHW is the employee hours worked

To calculate the injury rate, divide the number of injuries by the number of hours. Multiply by 200,000 to express it in the standard per 200,000 hours metric.

Injury Rate Definition

An injury rate is defined as the rate at which employees get injured on a job per 200,000 hours worked.

Injury rate and incident rate are often used interchangeably, but in some cases, companies like to keep these separate since incident rates include illnesses and injury rates may not.

This allows a company to distinguish between injury and illness.

Example Problem

How to calculate an injury rate?

First, determine the total number of employee hours that have been worked in the time period. For this example, the time period is 2 months and the number of hours worked is 500,000.

Next, determine the total number of injuries during that time period. There were officially 10 recorded injuries during that time span.

Finally, calculate the injury rate using the formula above:

IR = (I * 200,000) / EHW

IR = ( 10 * 200,000) /500000

IR = 4 injuries per 200,000 hours worked


What is the significance of the 200,000 hours metric in calculating injury rates?

The 200,000 hours metric is a standard benchmark used in calculating injury rates to provide a consistent basis for comparison across different industries and time periods. It represents the equivalent of 100 employees working full-time for one year, allowing companies to compare safety performance in a standardized way.

Can the injury rate formula be used for calculating illness rates as well?

Yes, the injury rate formula can also be adapted to calculate illness rates by substituting the number of illness cases for the number of injuries. However, some organizations prefer to keep these metrics separate to distinguish between workplace injuries and illnesses.

Why might a company choose to separate incident rates and injury rates?

A company might choose to separate incident rates from injury rates to more accurately track and respond to specific types of workplace hazards. By distinguishing between injuries and illnesses, a company can tailor its safety protocols and prevention strategies to address each category’s unique risk factors.

How can understanding injury rates improve workplace safety?

Understanding injury rates can help employers identify trends and areas of risk within their operations, allowing them to implement targeted safety measures. By analyzing injury rate data, companies can prioritize safety improvements, reduce workplace hazards, and foster a culture of safety among employees.