TRIR and DART rate calculator
Enter your recordable cases, DART cases and total hours worked. The arithmetic runs in your browser — nothing you type is sent to EHSTEC, stored, or put in the address bar.
Calculate your rates
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The two formulas
Both are incidence rates: they express how many cases occurred per 100 full-time-equivalent employees over a year, which is what makes a 40-person contractor and a 4,000-person manufacturer comparable at all.
Where 200,000 comes from
200,000 is the number of hours 100 employees work in a year at 40 hours a week for 50 weeks (100 × 40 × 50). It is not a safety constant or a legal threshold — it is the normalizing base that turns a raw case count into a rate you can compare across employers of different sizes.
What counts as an OSHA-recordable case
Under 29 CFR 1904.7(a), a work-related injury or illness is recordable if it results in any of the following:
- death
- days away from work
- restricted work or transfer to another job
- medical treatment beyond first aid
- loss of consciousness
- a significant injury or illness diagnosed by a physician or other licensed health care professional
Deciding whether a specific case meets one of those criteria is a factual judgement about work-relatedness and treatment. No calculator can make it for you, and this one does not try.
What counts toward DART
DART counts the recordable cases that cost time or capacity: those recorded in column H (days away from work) plus column I (job transfer or restriction) of the OSHA Form 300.
DART qualification comes from the outcome of a case, not from what kind of incident it was. A case becomes a DART case because someone missed work, was put on restricted duty, or was transferred — not because of how the injury is categorised.
The distinction people get wrong
DART is a subset of your recordable cases, but it is not simply "the serious ones". A fatality is recordable and counts toward TRIR, but it is recorded in column G — so it does not enter the DART numerator. A company can have a fatality and a DART rate of zero. That is one reason neither rate should be read as a measure of how safe a workplace is.
Where a case involves an extended absence, OSHA lets you cap the count at 180 calendar days (1904.7(b)(3)(vii)). The cap affects the day count you record, not whether the case is a DART case.
TRIR and DART compared
| TRIR | DART rate | |
|---|---|---|
| Numerator | all recordable cases (300 Log columns G, H, I and J) | columns H and I only |
| Includes a fatality? | yes | no |
| Includes first aid only? | no | no |
| Includes a near miss? | no | no |
| Constant | 200,000 | 200,000 |
A worked example
Hypothetical figures, for illustration only. These are not EHSTEC customer data, not an industry average, and not a target.
A fictional employer records 3 recordable cases in the year. One of them involved days away from work, so it is 1 DART case. Employees worked 400,000 hours.
A TRIR of 1.50 means roughly 1.5 recordable cases per 100 full-time-equivalent employees per year. It does not mean the employer is safe, unsafe, compliant or non-compliant.
What these rates do not tell you
- They are lagging indicators. They describe harm that already happened, and say nothing about the hazards still present.
- Small denominators are volatile. At a 50-person site, a single recordable case can move TRIR by several points. Year-on-year movement at that scale is often noise, not a trend.
- Under-reporting lowers both rates. A falling rate can mean fewer injuries or a workforce that has stopped reporting them. The rate alone cannot distinguish the two.
- Neither measures severity. One catastrophic injury and one case of stitches count the same in TRIR.
- Neither establishes compliance. A low rate is not a defence, a certification, or evidence that your recordkeeping is correct.
If you want to compare your rate against others, use published incidence-rate data for your own industry classification from the Bureau of Labor Statistics. We deliberately do not publish a "good" TRIR figure here: a number without your industry, your size and the survey year attached to it would be meaningless, and inventing one would be worse.
Getting the hours right
The denominator is where most calculations go wrong. Use actual hours worked by all employees covered by the log — including overtime — and exclude vacation, sick leave, holidays and any other paid non-working time. If you only have payroll hours that include paid leave, your rate will read lower than it should.
Sources
This page explains a calculation. It is not legal advice.
Whether a specific case is recordable, and how it should be classified, depends on facts this page cannot see. Nothing here is endorsed or approved by OSHA, and calculating a rate does not make an employer compliant. See our editorial standards for how this content is written and reviewed.