TRIR, DART, LTIR and the Others: Which Rate Is Which

Workplace-safety writing throws around a cluster of acronyms — TRC/TRIR, DART, DAFW, DJTR, LTIR, severity — as if they were all equally official. Four of them are: OSHA's forms package and BLS's own release define TRC/TRIR, DART, DAFW and DJTR down to the formula. The other two are industry shorthand that neither agency defines anywhere in the sources this site holds. This page lays out all six side by side, so the difference between a defined term and a borrowed one is visible at a glance.

The six rates, side by side

OSHA and BLS define four of these; two are shorthand nobody owns

OSHA's recordkeeping forms package states the TRC formula in one line and the DART formula in the next — both quoted in full on the two calculators linked in the table above. BLS defines DAFW and DJTR too, in its own words: "Cases involving days away from work, job transfer, or restriction (DART) are the sum of cases with days away from work (DAFW) and cases involving only days of job transfer or restriction (DJTR)." Every one of those four terms traces to a named federal source with a stated formula or a stated definition.

"LTIR" doesn't, and neither does "severity rate" as an injury-count metric. Neither the OSHA forms package nor the BLS release saved here defines either term, gives it a formula, or even uses it. That doesn't mean no one anywhere ever spells out what their own "LTIR" counts — a company or a consultant may define it for their own report — but it does mean the label itself carries no fixed, federally defined meaning the way TRC or DART does. If a number is handed to you labeled "LTIR" without saying which cases it counts, there's no federal source to check it against.

DART is DAFW plus DJTR, not a separate count

BLS's own definition makes DART a sum, not an independent measure: DAFW cases (days away from work) plus DJTR cases (only job transfer or restriction, with no days away) add up to DART. The DART rate calculator computes the identical sum from your OSHA 300 Log — columns H and I — without needing to know which case belongs to which of the two. Over 2023-2024, BLS's own release put DAFW cases at an annualized rate of 86.6 per 10,000 FTE workers nationally and DJTR cases at 54.2 per 10,000 FTE workers; neither figure stands in for DART, and neither is this site's own benchmark — the TRIR calculator cites only the one confirmed private-industry TRC figure, 2.3 per 100 FTE workers in 2024.

Reading someone else's LTIR or severity figure

If a report, a competitor's site or a contractor's safety packet cites an "LTIR" or a "severity" figure, there's no OSHA or BLS formula behind it to check the number against, and no guarantee two organizations are counting the same cases under that label. NCCI's own document uses the word severity too, but for something different — dollar amounts of loss, split into primary and excess portions, feeding the experience modification rate rather than a rate per 100 workers. The shared name is a reason to ask what's being counted before comparing a figure like that to your own, not a reason to assume the two line up.

Run your own numbers

Every defined rate on this page traces back to the same OSHA 300 Log. The TRIR calculator works out TRC/TRIR, the DART rate and the days-away case rate from your 300A totals; the DART rate calculator leads with DART specifically, for a shop that only wants that one figure; and the hours worksheet gets you the hours-worked total both calculators need if you don't already have it from payroll. None of the three touches "LTIR," severity or a mod — only the rates a saved federal source actually defines.