How this calculator works
The total recordable incident rate, or TRIR, compares the number of recordable work injuries with the hours worked. It exists because a raw injury count is meaningless without knowing how many people worked and for how long: a warehouse with 500 staff and 8 injuries may be safer than a workshop with 20 staff and 2 injuries. The rate divides cases by hours and multiplies by 200,000, the number of hours 100 full-time workers log in a year at 40 hours a week for 50 weeks. The result reads as the number of recordable cases per 100 full-time equivalent workers per year. Recordable means more than a minor scrape: it covers injuries and illnesses that need medical treatment beyond first aid, involve loss of consciousness, restrict work or require days away, as defined in the OSHA recordkeeping rules. First-aid-only cases are not recordable. The rate can be reverse-engineered to answer planning questions, such as how many cases a given number of hours would imply at a target rate, or how many hours a contractor must work before a case count is expected. Recordkeeping habits change the rate a lot, especially in small firms and after a change in safety staffing, so compare a site with its own history and with similar operations rather than with a headline number.
Formula
TRIR = (number of recordable incidents x 200,000) / hours worked. Cases = TRIR x hours / 200,000. Hours = cases x 200,000 / TRIR. The 200,000 constant is 100 full-time equivalents x 40 hours x 50 weeks.
Worked example
A company records 5 recordable incidents across 500,000 hours. The TRIR is 5 x 200,000 / 500,000 = 2.0 cases per 100 full-time workers. At a target TRIR of 1.5, the same 500,000 hours would allow 1.5 x 500,000 / 200,000 = 3.75 cases, so the company is above its target. With 250,000 hours and 5 cases, the rate doubles to 4.0, showing how much the hours base matters.
Advertisement
Frequently asked questions
What is the difference between TRIR and DART?
TRIR counts all recordable cases. DART counts only the subset that involved days away from work, restricted duty or a transfer. DART is therefore always lower than or equal to TRIR for the same hours.
Which hours should be included?
All hours worked by everyone covered by the employer's recordkeeping obligation, including overtime and part-time hours. Be consistent about contractors from year to year, because mixing them in and out distorts the trend.
What is a good TRIR?
It depends on the industry and the work. Industries with high-hazard work have higher rates by nature. Compare with the Bureau of Labor Statistics rates for your industry and with your own multi-year average rather than with a single figure.
Does TRIR include illnesses as well as injuries?
Yes. Recordable work-related illnesses, such as occupational asthma or hearing loss, count alongside injuries if they meet the recording criteria. The reporting rules define what qualifies.
Can TRIR be calculated for a fraction of a year?
Yes. Use the hours actually worked in the period. The 200,000 constant is an annual base but the ratio still works for a quarter or a month; the figure then reads as an annualised rate for that period.