OSHA incident rate calculator (TRIR and DART)
Enter your OSHA 300 Log case counts and total hours worked to get rates per 100 full-time workers.
Rates are per 100 full-time-equivalent workers.
Formula and source
Rate = (N × 200,000) ÷ EH
N = number of cases of that type. EH = total hours worked by all employees during the year.
“(Number of injuries and illnesses X 200,000) / Employee hours worked = Incidence rate (The 200,000 hours in the formula represents the equivalent of 100 employees working 40 hours per week, 50 weeks per year, and provides the standard base for the incidence rates.)”
“The same formula can be used to compute the incidence rate for the most serious injury and illness cases, defined here as cases that result in workers taking time off from their jobs or being transferred to another job or doing lighter (restricted) duties.”
FAQ
What is the OSHA incident rate formula?
Incidence rate = (number of cases × 200,000) ÷ total hours worked by all employees. The 200,000 represents 100 employees working 40 hours a week for 50 weeks, so the result is cases per 100 full-time workers (BLS).
What counts toward DART?
DART counts cases involving days away from work, job restriction, or job transfer, which are columns H and I on the OSHA 300 Log. Other recordable cases (column J) are excluded.
Which hours should I use?
Use hours actually worked. BLS says hours worked should not include non-work time, even when paid, such as vacation, sick leave or holidays.
Incidence rate math is part of ASP11 Domain 1. Try cited practice problems in safety calculations or take the free diagnostic.