Free TRIR Calculator — Know Your Number Before Someone Asks For It

TRIR, DART, LTIR, and severity rate — calculated from your OSHA 300 log

The TRIR formula

TRIR = (number of OSHA recordable cases × 200,000) ÷ total hours worked

The 200,000 is a fixed base: 100 full-time employees working 40 hours a week for 50 weeks. It puts every company on the same scale, so a 12-person shop and a 500-person plant can be compared directly.

Example: your crews worked 150,000 hours last year and you had 3 recordable injuries.

3 × 200,000 ÷ 150,000 = TRIR of 4.0

For context, the Bureau of Labor Statistics put the all-industry private employer rate at 2.3 recordable cases per 100 full-time workers in 2024 — the most recent year published. What counts as “good” varies a lot by industry — compare yourself to your own NAICS code, not the national number.

The other three rates that ride along with it

• DART rate — same formula, but it only counts cases with Days Away, Restricted duty, or job Transfer. It measures how many of your injuries were serious enough to change someone’s work.
• LTIR (lost time incident rate) — only counts cases where someone missed work entirely.
• Severity rate — total days lost or restricted × 200,000 ÷ hours worked. Two companies can have the same TRIR while one loses ten times the workdays; this is the number that shows it.

Why your TRIR follows you around

General contractors and project owners ask for TRIR in prequalification packets — usually the last three years of it, alongside your EMR and OSHA logs. Insurance underwriters look at the same history when they price your workers’ comp. A high number doesn’t just describe last year; it prices next year and decides which bid lists you make.

The uncomfortable part: you can’t calculate an honest TRIR without an honest 300 log. If injuries aren’t getting reported, your number looks great right up until an audit or a claim says otherwise. (That’s a culture problem before it’s a math problem — our free near-miss reporting toolbox talk is where most companies start.)

How the free calculator works

This isn’t a bare form where you type two numbers. The calculator is one tab of our free OSHA recordkeeping app:

1. Log incidents (or check whether they’re even recordable — the app walks you through OSHA’s 1904 criteria).
2. Enter your establishment info and total hours worked.
3. TRIR, DART, LTIR, and severity rate generate automatically — no formulas to remember, no spreadsheet to break.

Your log entries are saved in your own browser’s local storage — on your machine, not on our servers — and there’s no account to create. Because the log lives in your browser, clearing your browser data clears it — export to Excel and keep that file as your durable copy.

Need the year-end paperwork too? The same app generates your OSHA 300A summary from the same log.