Caution

TRIR Calculator

Total recordable incident rate, DART rate, and the arithmetic shown rather than hidden. Enter the case counts off your 300 log and the hours worked for the same period.

Stencil print of a calculator beside a stack of sheets — A calculator beside a stack of ruled sheets \u2014 the rate is only as good as the log behind it.

Pre-filled with a plausible 150-worker year. Change any number — the result updates instantly, with no count-up.

Inputs

Recordable casesColumn totals from the 300 logDART casesDays away, restricted or transferredHours workedAll employees, the same period

Result

3.87

TRIR — total recordable incident rate

1.94

DART rate

In the band where a GC will ask for your 300 logs and a corrective-action narrative.

The arithmetic, shown

TRIR = (recordable cases × 200,000) ÷ hours worked

TRIR = (6 × 200,000) ÷ 310000 = 3.87

DART = (DART cases × 200,000) ÷ hours worked

DART = (3 × 200,000) ÷ 310000 = 1.94

Where 200,000 comes from

TRIR = (recordable cases × 200,000) ÷ hours worked. The constant is 100 full-time equivalent workers at 40 hours a week for 50 weeks. It exists so a 20-person shop and a 2,000-person contractor produce comparable numbers.

DART uses the same base but counts only cases with days away, restricted work or job transfer — the subset from 1904.7(b)(4) and (b)(5). DART is always less than or equal to TRIR.

Caution

Both rates are hostage to their denominator. Hours worked has to cover every employee in the same period as the case count — including part-time and seasonal — or the rate is fiction in your own favour.

Reading the number honestly

A small contractor's rate is statistically noisy. On 100,000 hours — roughly 50 workers for a year — a single recordable moves TRIR by 2.0. That is why a prequalification package asks for three years, and why a one-year improvement is not a trend.

It is also why suppressing a rate is so tempting and so obvious. A TRIR near zero across several years with a payroll in the hundreds usually means cases are being managed off the log, and any competent prequalifier reads it that way.

What to report beside it

DART, because severity matters more than count.
Hours worked, so the reader can judge the noise.
Leading indicators — inspections completed, near misses reported, corrective actions closed — which move before the lagging rate does.
Your EMR, which the insurer calculates and you cannot; see EMR rating explained.

The three lagging numbers are compared side by side in TRIR vs DART vs EMR.

Sources, with the date each was read

29 CFR 1904.7 — General recording criteria (OSHA)read 2026-09-04
29 CFR 1904.32 — Annual summary (OSHA)read 2026-09-04