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TRIR and DART rate calculator
TRIR, the total recordable incident rate, is the number of OSHA recordable injuries and illnesses per 200,000 hours worked, about 100 full-time workers for a year. The DART rate counts only the cases with days away from work, restricted work or a job transfer. Enter your OSHA 300A case counts and hours to get both.
TRIRequals(G + H + I + J) × 200,000 divided by Hours worked
DART rateequals(H + I) × 200,000 divided by Hours worked
Days-away rateequalsH × 200,000 divided by Hours worked
Form 300A or payroll. Leave out vacation, sick leave and holidays.
H, I, J and G are the case columns on OSHA Form 300A, and each case is in one column only, so nothing is counted twice. Pre-filled with the worked example.
TRIR, per 200,000 hours
2.87
7 recordable cases in 487,200 hours, about 244 full-time workers.
DART rate
1.23
3 in H + I
One more case adds
+0.41
To the rate at these hours
Days-away rate (H)
0.82
Some call it a lost time rate
Per million hours
14.37
Recordable frequency rate
Rolling 12 months, month by month
Enter each month's hours, recordable cases and DART cases (the cases in columns H and I). The 12-month rate adds up the cases and the hours first, then applies the formula once. Pre-filled with the worked example's year, month 1 being the oldest. Per 200,000 hours.
12-month TRIR
2.87
7 cases, 487,200 h
12-month DART
1.23
3 DART cases
Single months run from 0.00 to 10.36, because one case is a large share of one month's hours. The plain average of the monthly rates is 2.91; it is not the 12-month rate, because it gives a short month the same weight as a long one.
Next step
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What goes into the formula
Which cases count, and which hours
A case is recordable when it is work-related, a new case, and meets at least one general recording criterion (29 CFR 1904.4). The criteria in 1904.7 are death, days away from work, restricted work or job transfer, medical treatment beyond first aid, loss of consciousness, or a significant injury or illness diagnosed by a physician or other licensed health care professional. Cancer, chronic irreversible disease, a fractured or cracked bone and a punctured eardrum are always recordable at diagnosis, even with no treatment.
First aid is not recordable, and the first aid list in 1904.7(b)(5)(ii) is complete: for example non-prescription medicine at non-prescription strength, cleaning and covering a wound, butterfly bandages or Steri-Strips, hot or cold therapy, elastic wraps and other non-rigid supports, and removing a splinter with tweezers. Sutures, staples, physical therapy and rigid supports that immobilize a body part are medical treatment. It does not matter who gives it: first aid from a physician is still first aid.
Each case goes in one column, its most serious outcome: G (death), then H (days away), then I (job transfer or restriction), then J (other recordable), as the OSHA 300 Log instructions say. A case with days away and restricted days is an H case, so DART is H + I with nothing to subtract. Days are counted from the day after the injury, and a restriction only on the day of the injury does not make it a restricted case (1904.7(b)(3) and (b)(4)).
Hours worked are the hours everyone on the log actually worked: hourly, salaried, part-time and seasonal staff, and temporary workers you supervise day to day (1904.31). Leave out vacation, sick leave, holidays and other paid time not worked. Without payroll hours, choose “Estimate it”, which follows the optional worksheet on Form 300A. Keep one rate per establishment, as OSHA keeps one log per establishment (1904.30).
This page explains the rules so the arithmetic is right. Whether a particular case is recordable is a judgment against 1904.4 to 1904.12; when in doubt, read the section or ask your safety professional.
Worked example
Illustrative numbers, not a benchmarkA plant with 230 full-time employees and some part-time and temporary staff it supervises day to day. Its 300A for the year shows 2 cases with days away (H), 1 with restricted work (I), 4 other recordable cases (J), such as cuts closed with sutures, and no deaths (G).
- 1Hours = 230 × 2,000 + 27,200 hours of overtime, part-time and temporary work = 487,200 hours.
- 2Recordable cases = 0 + 2 + 1 + 4 = 7. DART cases = 2 + 1 = 3.
- 3TRIR = 7 × 200,000 ÷ 487,200 = 2.87.
- 4DART rate = 3 × 200,000 ÷ 487,200 = 1.23. Days-away rate = 2 × 200,000 ÷ 487,200 = 0.82.
- 5One case = 200,000 ÷ 487,200 = 0.41 points: an eighth case would make the TRIR 3.28.
- 6Per 1,000,000 hours: 7 × 1,000,000 ÷ 487,200 = 14.37.
What to do with the number
Trend it against yourself first. Track the rolling 12-month TRIR and DART each month. At under 200,000 hours a year one case moves the rate by more than a full point, so a small plant should look at several years before calling a change real.
Compare with your industry, by NAICS code. Form 300A asks for the code. Find it in BLS Table 1 for 2024, which gives total recordable and DART rates down to 4 to 6 digit industries, or enter your numbers in the BLS incidence rate calculator, which compares them for you. Compare a full calendar year, and round to one decimal as BLS does. Detailed codes can differ a lot from their subsector: motor vehicle manufacturing (3361) was 5.6 in 2024, against 3.2 for transportation equipment (336).
Read TRIR and DART together. DART shows how many cases took someone off their normal job. A falling TRIR with a flat DART means fewer minor cases, not fewer serious ones.
Do not reward a low number. A reporting procedure that would deter or discourage a reasonable employee from reporting is not reasonable under 1904.35(b)(1)(i), and retaliating against someone for reporting is prohibited. Put leading indicators next to the rate, such as near-miss reports and a safety cross, and take each recordable case into an incident investigation.
The 300A summary for the year must be posted from February 1 to April 30 of the next year (1904.32). Work out the yearly rate from the same certified 300A totals, so the posted summary and the rate you report match.
Manufacturing rates, 2024
Cases per 100 full-time workers (per 200,000 hours), U.S. private industry, by 3-digit NAICS subsector. Nonfatal cases, so compare with the nonfatal rate if your log has a death.
| Industry | NAICS | TRIR | DART |
|---|---|---|---|
| All private industry | 2.3 | 1.4 | |
| All manufacturing | 31-33 | 2.7 | 1.7 |
| Food | 311 | 3.3 | 2.3 |
| Beverage and tobacco products | 312 | 3.7 | 2.6 |
| Textile mills | 313 | 2.5 | 1.6 |
| Textile product mills | 314 | 2.1 | 1.3 |
| Apparel | 315 | 1.9 | 1.2 |
| Leather and allied products | 316 | 4.0 | 2.7 |
| Wood products | 321 | 4.2 | 2.7 |
| Paper | 322 | 2.4 | 1.6 |
| Printing and related support | 323 | 1.6 | 1.0 |
| Petroleum and coal products | 324 | 1.0 | 0.6 |
| Chemicals | 325 | 1.6 | 1.0 |
| Plastics and rubber products | 326 | 2.8 | 1.8 |
| Nonmetallic mineral products | 327 | 3.3 | 2.0 |
| Primary metals | 331 | 3.3 | 2.0 |
| Fabricated metal products | 332 | 3.2 | 1.8 |
| Machinery | 333 | 2.3 | 1.3 |
| Computer and electronic products | 334 | 0.9 | 0.5 |
| Electrical equipment, appliances and components | 335 | 2.0 | 1.2 |
| Transportation equipment | 336 | 3.2 | 2.1 |
| Furniture and related products | 337 | 3.5 | 2.1 |
| Miscellaneous manufacturing | 339 | 1.7 | 0.9 |
Source: U.S. Bureau of Labor Statistics, Survey of Occupational Injuries and Illnesses, Table 1, incidence rates by industry and case types, 2024 (last modified January 22, 2026). Checked October 9, 2026.
Common mistakes
- Adding the DART cases to the total recordable cases. DART cases are already in the total.
- Using paid hours. Vacation, sick leave and holidays in the hours make the rate look lower than it is.
- Averaging monthly or plant rates. Add up the cases and the hours, then divide once.
- Counting temporary workers' hours but not their cases, or the other way round. Both sides must cover the same people.
- Counting first aid or a check-up visit as recordable, or missing a fracture because no treatment was given. A fracture is recordable at diagnosis.
- Moving a case into the next year because the days away ran past December 31. A case is recorded once, in the year it happened (1904.7(b)(3)(ix)).
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<p style="font:13px/1.4 sans-serif"><a href="https://www.theleansuite.com/tools/trir-dart-calculator">TRIR and DART rate calculator</a> by LeanSuite</p>How LeanSuite helps
LeanSuite reports incident rates (TRIR and DART) next to near misses and leading indicators such as safety observations, Gemba walks and completed JSAs, so safety leaders see high-risk areas and trends.
See Continuous Improvement for SafetyRead more
- Free template: Manufacturing KPI dashboard template
- Free template: Incident investigation report template
- Free template: Near miss report form
- Free template: ISO 45001 internal audit checklist
- Total recordable incident rate (TRIR) in the lean glossary
- DART rate in the lean glossary
- Leading and lagging indicators
- Manufacturing safety statistics, with sources
- Safety management guides
- OSHA Audit Preparation: Reducing 40 Hours to 4 Hours
FAQ
TRIR and DART rate calculator: common questions
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