TRIR Calculator

What Is TRIR?

TRIR (Total Recordable Incident Rate) — sometimes called the OSHA recordable incident rate — measures how many OSHA-recordable work-related injuries and illnesses a company had per 100 full-time employees over a year. It's the primary safety-performance metric OSHA, insurers, and prime contractors use to compare companies of different sizes on an equal footing, since raw incident counts alone don't account for how many hours a workforce actually worked.

Employers required to keep OSHA injury and illness records calculate TRIR from their OSHA 300 Log and report it (along with DART rate) on the annual OSHA 300A Summary. A lower TRIR generally signals fewer recordable incidents relative to hours worked — better safety performance — while a rising TRIR is usually treated as an early warning sign worth investigating.

TRIR Formula

Both figures must cover the same time period — almost always one calendar year. Recordable incidents come straight off the OSHA 300 Log; total hours worked is the sum of actual hours worked by every employee (not a headcount-based estimate) during that same period. The 200,000 constant (100 full-time workers × 40 hours/week × 50 weeks/year) is fixed by OSHA and never changes.

How to Calculate TRIR

1. 1Pull the total count of OSHA-recordable incidents for the period from your OSHA 300 Log.
2. 2Add up total hours actually worked by every employee over that same period (not a headcount estimate).
3. 3Multiply the recordable incident count by 200,000.
4. 4Divide that result by total hours worked.
5. 5Round to two decimal places — this is your TRIR.

TRIR vs. DART vs. Other Incident Rates

"Incident rate" is often used as a general synonym for TRIR, but a few related rates use the same 200,000-hour formula with a narrower incident count in the numerator:

• TTRIR (Total Recordable Incident Rate): every OSHA-recordable incident — the broadest of these rates, and the one usually just called "incident rate."
• DDART (Days Away, Restricted, or Transferred): a subset of TRIR — only recordable incidents severe enough to cause days away from work, restricted duty, or a job transfer. Every DART case is already counted inside TRIR; it's never added separately.
• LLTIR / LWCR (Lost Time Incident/Case Rate): narrower still — only incidents that caused at least one full day away from work, excluding restricted-duty or transfer cases that DART includes.

All three use the same (Incidents × 200,000) ÷ Total Hours Worked formula — only which incidents get counted in the numerator changes.

What Is a Good TRIR?

There's no single "good" TRIR that applies across every industry — a rate that's excellent for an office environment would be alarming for a roofing contractor. The standard reference point is your industry's average TRIR for the same NAICS code, published annually by the Bureau of Labor Statistics (BLS); many prime contractors and insurers also set their own maximum acceptable TRIR for bidding or underwriting. Lower is always better within a given industry, and a TRIR trending down year over year matters more than any single point-in-time number.

Common Mistakes & Edge Cases

• Counting first-aid cases as OSHA recordablesNot every workplace injury is OSHA-recordable. First-aid-only treatment (per the specific list in 29 CFR 1904.7, e.g. a bandage, an over-the-counter pain reliever at nonprescription strength, a single dose of a prescription-strength medication) does not count, even if the injury happened at work. Including first-aid cases in the incident count inflates TRIR above what OSHA would actually calculate from the same data.
• Using average or scheduled headcount instead of actual hours workedThe denominator is total hours actually worked by all employees during the period — not headcount x a standard 2,080-hour year. Overtime, part-time schedules, seasonal staffing, and unpaid leave all move actual hours away from the "assumed" figure, and using the wrong one changes the rate in either direction.
• Comparing a partial-year TRIR to a full-year industry averageA TRIR calculated from 3 months of data is not directly comparable to a full-year BLS industry average — short reporting windows are more volatile and a single incident swings the rate much further. Annualize the hours-worked figure (or wait for a full 12-month period) before benchmarking against published industry rates.
• Assuming DART and TRIR are the same numberDART is a subset of TRIR, not a separate incident count. Every DART case (one involving days away, restricted duty, or job transfer) is also a recordable incident and is already included in the TRIR count — it should not be added on top of it when totaling incidents.

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