DART Rate & TRIR Calculator

What Is the DART Rate?

The DART rate — Days Away, Restricted, or Transferred — tracks the subset of recordable incidents that result in lost workdays, restricted duty, or a job transfer. Because it focuses on the more severe cases, many organizations consider it a better indicator of serious safety issues than TRIR alone.

The formula is: DART = (Number of DART Cases × 200,000) ÷ Total Hours Worked. A DART case is any recordable incident where the employee had days away from work, was placed on restricted duty, or was transferred to a different job.

A Worked Example

A 48-employee fabrication shop works 96,000 hours in a year. Over that year it logs six recordable cases: two required stitches and nothing more, one caused nine days away from work, one moved an employee to light duty for three weeks, one was a hearing-loss case with no work restriction, and one was a laceration treated with prescription antibiotics.

• TRIR counts all six: (6 × 200,000) ÷ 96,000 = 12.5
• DART counts only the days-away case and the restricted-duty case: (2 × 200,000) ÷ 96,000 = 4.17

Every DART case is also a TRIR case, so DART can never exceed TRIR. If your calculation produces a DART rate higher than your TRIR, something has been miscounted — usually a case classified as days-away on the log without being counted as recordable in the total.

Which Cases Count Toward DART?

DART covers the cases marked in columns H (days away) and I (job transfer or restriction) on the OSHA 300 log. Cases in column J — “other recordable cases” — are recordable but not DART. The distinction is about outcome, not severity of the injury itself: a case needing surgery but no time away is a TRIR case only, while a sprain that keeps someone off the floor for two days is both.

Two counting rules trip people up. Day counts run in calendar days, not scheduled workdays — weekends and holidays count if the employee would have been unable to work — and the count is capped at 180 days per case (1904.7(b)(3)(viii)). The day of the injury itself is never counted; counting starts the following day.

How to Calculate Total Hours Worked

Total hours worked includes all hours actually worked by all employees during the year — including overtime but excluding vacation, sick leave, holidays, and other non-work time. It covers everyone whose injuries you would record: full-time, part-time, seasonal, and temporary workers you supervise on a day-to-day basis.

If you don’t track exact hours, OSHA’s 300A worksheet allows an estimate: Number of Employees × Average Hours per Week × Weeks Worked. For a quick approximation, multiply average headcount by 2,000 (40 hours × 50 weeks). Salaried and exempt staff still contribute hours — use their scheduled hours rather than omitting them, which would understate the denominator and inflate your rate.

Rates are calculated per establishment, so a multi-location employer computes hours and cases separately for each site. That is also how OSHA and most pre-qualification systems read them — a company-wide average can hide a single location driving the whole number. See one log per location for how the establishment boundary is drawn.

What Counts as a “Good” Rate?

There is no universal target. A TRIR of 3.0 is unremarkable in heavy manufacturing and alarming in professional services, so the only meaningful comparison is against your own industry. The Bureau of Labor Statistics publishes annual incidence rates by NAICS industry through its Survey of Occupational Injuries and Illnesses (SOII) — that is the benchmark OSHA, insurers, and pre-qualification systems actually use.

Treat a single year’s rate with caution at small headcounts. At 96,000 hours, one additional recordable case moves TRIR by more than two full points. For a shop with 20 employees, the difference between a “good” and “bad” year can be a single sprained ankle — which is why trend across several years is more informative than any one number.

Why Your Rates Matter

Your TRIR and DART rates influence your Experience Modification Rate (EMR), which determines your workers’ compensation premiums, and they are routinely requested during contractor pre-qualification — particularly in construction, oil & gas, and manufacturing, where a rate above the industry average can disqualify a bid outright.

OSHA also uses rate data to target enforcement. Establishments whose rates run significantly above their sector’s average are more likely to be selected for a programmed inspection under the Site-Specific Targeting program — which draws directly from the 300A data establishments submit electronically.

Common Questions

Why 200,000 and not 100,000?

The constant normalizes rates to 100 full-time equivalent workers: 100 workers × 40 hours × 50 weeks = 200,000 hours. It has no regulatory meaning of its own — it just makes rates comparable across employers of different sizes, and matches how BLS publishes industry rates.

Do first-aid-only cases count toward TRIR?

No. Only OSHA-recordable cases count. If a case did not meet a recording criterion it never reaches your rate — which is why getting recordability right matters more to your rate than anything you do downstream.

Are TRIR and TCIR the same thing?

Yes. Total Recordable Incident Rate and Total Case Incidence Rate are the same calculation under different names; BLS uses TCIR (or “total recordable cases”), while contractors and insurers usually say TRIR.

Do temporary or staffing-agency workers count?

They count for whichever employer supervises them day to day — usually the host employer, who records their injuries and includes their hours. Host and staffing agency responsibilities covers how to split this without double-counting.

Does a case still count if workers’ comp denied the claim?

Yes. Recordability and compensability are independent tests — a denied claim has no bearing on whether the case belongs on your log or in your rate.

More on rate mechanics in TRIR and DART explained for small employers, or browse all recordkeeping guides.