Calculating OSHA Injury and Illness Incidence Rates

Each year, the Occupational Safety and Health Administration (OSHA) collects work-related injury and illness data from employers. This data collection is called the OSHA Data Initiative (ODI).

The data provided is used by OSHA to calculate establishment-specific injury and illness incidence rates. An incidence rate is the number of recordable injuries and illnesses occurring among a given number of full-time workers (usually 100 full-time workers) over a given period of time (usually one year).

An employer may want to evaluate its injury and illness experience over time or compare its experience with that of the industry as a whole. This is called an employer’s incidence rate. These rates can help identify problems in the workplace and progress made in preventing work-related injuries and, horst insurance, calculating OSHA injury and incidence rates


Computing the Incidence Rate

Employers can use a formula to compute an occupational injury and illness incidence rate for all recordable cases or for cases that involved days away from work. Before computing the rate, employers must determine:

  • Total recordable cases – The total case rate (TCR) includes all cases recorded on the OSHA Form 300 (Column G + Column H + Column I + Column J).
  • Cases involving days away from work – The days away, restricted and transferred (DART) includes cases recorded in Column H + Column I. The days away from work (DAFW) includes cases recorded in Column H.
  • Total hours all employees actually worked during the year – Refer to OSHA Form 300A and optional worksheet to calculate this number.



Once the items described above are determined, an employer can compute the incidence rate of injuries and illnesses using the following formula:

(Number of injuries and illnesses x 200,000)/Employee hours worked

**The 200,000 figure in the formula represents the number of hours that would be worked by 100 employees working 40 hours per week, 50 weeks per year. It provides the standard base for calculating incidence rates.**

For further information on injury and illness incidence rates, please visit the Bureau of Labor Statistics website at