Assumes 2,000 hours per employee per year, which is the same full-time assumption behind the 200,000 constant. Use real hours if you have them.
Based on 100,000 hours worked. TRIR = (3 × 200,000) ÷ 100,000.
Why 200,000
The constant is one hundred full-time employees working forty hours a week for fifty weeks. Dividing by hours worked and multiplying by that figure turns a raw case count into a rate per hundred workers, which is the only way a company of twelve and a company of four thousand can be compared at all.
It also means the rate is sensitive to hours. A quiet quarter with fewer hours worked raises your rate even with the same number of incidents, which is worth knowing before you report a jump to a board.
Recordable, DART, lost time
These three count progressively narrower sets of the same incidents. Every DART case is a recordable. Every lost-time case is a DART case. If your TRIR is high but DART is near zero, you are recording plenty of minor treatment cases and few that stop anyone working, which is a different problem from the reverse.
Common questions
What is the TRIR formula?
TRIR equals the number of OSHA recordable cases multiplied by 200,000, divided by the total hours worked in the period. The 200,000 is a constant representing one hundred full-time employees working forty hours a week for fifty weeks, which is what makes rates comparable between companies of different sizes.
What counts as a recordable case?
Under 29 CFR 1904, a case is recordable if it is work related and results in death, days away from work, restricted work or transfer to another job, medical treatment beyond first aid, loss of consciousness, or diagnosis of a significant injury or illness by a licensed health care professional.
What is the difference between TRIR and DART?
TRIR counts every recordable case. DART counts only the subset involving days away from work, restricted work or job transfer. DART is always the smaller number, and the gap between the two says how many of your recordables were serious enough to change what somebody could do.
What is a good TRIR?
It depends entirely on your industry, and there is no single target that means anything across sectors. The Bureau of Labor Statistics publishes incidence rates by NAICS code each year, and that is the only benchmark worth comparing yourself to. A rate that looks good against construction may be poor for an office.
Do I need actual hours worked, or is headcount enough?
Actual hours are correct and headcount is an estimate. If you use headcount this tool assumes 2,000 hours per employee per year, which is the same full-time assumption behind the 200,000 constant. Overtime, part-time staff and seasonal work all pull the real figure away from that.
Where the rate actually moves
A rate is a scoreboard, not a lever. The things that change it are the hazards your people meet most often, and enforcement data is a reasonable guide to which of those get overlooked.