TRIR Calculator

Compute OSHA total recordable incident rate from cases and hours worked.

Enter recordable incidents and total hours worked to calculate TRIR using the 200,000-hour OSHA base.

TRIR Calculator

Compute OSHA total recordable incident rate from cases and hours worked.

Total Recordable Incidents

Total Hours Worked

About OSHA TRIR

The total recordable incident rate, or TRIR, is the OSHA-normalized measure of how many recordable workplace injuries and illnesses occur per 100 full-time workers. Safety managers, contractors, and bid reviewers use TRIR to compare sites of different sizes on a common scale. The TRIR calculator multiplies recordable incidents by 200,000 hours, the OSHA convention for 100 employees working 40 hours a week for 50 weeks, and divides by hours actually worked. With 3 recordable cases and 300,000 hours, TRIR is 3 × 200,000 ÷ 300,000 = 2.00. With 5 cases and 800,000 hours, TRIR is 1.25. A small crew with 1 case and 50,000 hours posts a TRIR of 4.00, which looks high because a single case is spread over fewer hours. That sensitivity is why small employers should not treat one noisy year as a permanent safety grade. Recordable cases follow OSHA 29 CFR 1904: deaths, days away, restricted work, job transfer, loss of consciousness, and injuries requiring medical treatment beyond first aid. First-aid-only events and commuting incidents generally do not belong in the numerator. Hours should be actual hours worked, including overtime, and should exclude vacation, holiday, and leave time that OSHA does not count as hours worked. TRIR is an incident rate, not a severity rate. A year with one fatality and a year with three minor recordable strains can produce similar TRIRs. Pair the figure with DART, lost-time rate, and a narrative of serious events before you use it in a contractor prequalification. The calculator does not decide whether a case is recordable and does not replace OSHA Form 300 logs. Recalculate when hours are restated or when a case is reclassified after medical follow-up. Hours worked should cover the same calendar span as the incident count, typically a calendar year or a trailing twelve months used in a bid form. If you annualize a partial year, scale both incidents and hours or you will overstate the rate. Never mix fiscal-year hours with calendar-year cases. Document the log, the hour source, and the as-of date whenever TRIR is sent to a customer or an insurer.

TRIR Worked Examples

Each example uses recordable incidents × 200,000 ÷ hours worked.

Inputs	Result	Interpretation
3 recordable incidents, 300,000 hours worked	2	Equal to two cases per 100 full-time workers in the OSHA 200,000-hour year.
5 recordable incidents, 800,000 hours worked	1.25	A larger hour base lowers the rate even with more cases.
1 recordable incident, 50,000 hours worked	4	A single case at a small site produces a high TRIR because the denominator is small.

How to Calculate TRIR

Count OSHA-recordable incidents for the same period as the hours.
Enter total hours actually worked, including overtime and excluding most leave.
Select Calculate to apply the 200,000-hour OSHA normalization.
Compare the rate with the prior year or with a contractor prequalification threshold.

TRIR Calculator FAQ

What does the 200,000 in the TRIR formula mean?

It is 100 employees × 40 hours × 50 weeks. OSHA uses that base so a 10-person shop and a 1,000-person plant can be compared on the same scale.

Do first-aid cases count?

Usually no. OSHA recordable cases are more serious than first aid. Including first-aid events inflates TRIR and no longer matches Form 300 definitions.

Should I include contractor hours?

Only if those contractors are in your OSHA log for the same period. Mixing host-employer hours with contractor cases, or the reverse, produces a rate nobody else can audit.

Why is my small-site TRIR so volatile?

With few hours, one case moves the rate by a large amount. Look at a three-year average and at case severity before you treat a single-year TRIR as a trend.