TRIR is the number of recordable cases on your OSHA 300 Log, times 200,000, divided by the hours all employees worked in the year. DART counts only the cases in columns H and I, and LTIR only column H. OSHA requires the forms (29 CFR 1904.29(a)) and no rate at all; customers and prequalification services are the ones who ask for rates.
At a glance
- TRIR = (G + H + I + J) x 200,000 / hours worked.
- DART = (H + I) x 200,000 / hours worked.
- LTIR = H x 200,000 / hours worked, an industry measure with no OSHA definition.
- BLS 2024: 2.3 for private industry, 2.2 for construction, per 100 full-time workers.
How to calculate TRIR, DART and LTIR
All three rates use the Bureau of Labor Statistics formula, written in its survey notes as “(N/EH) x 200,000”, where N is the number of injuries and illnesses and EH the total hours worked by all employees during the calendar year. The 200,000 is the base for 100 full-time workers at 40 hours a week for 50 weeks, so every rate reads as cases per 100 full-time workers. Only the count N changes from one rate to the next.
OSHA prints the same two formulas on a page of its forms package headed “Optional”, for the total recordable case rate and the DART rate. That page counts the total either as “the number of line entries on your OSHA Form 300” or as the 300A entries for columns H, I and J, which leaves deaths out. The two only differ in a year with a death in column G, and the calculator then shows both.
| Rate | Cases counted (OSHA 300 Log column) | Formula |
|---|---|---|
| TRIR | All recordable cases: G deaths, H days away, I job transfer or restriction, J other | (G + H + I + J) x 200,000 / hours |
| DART | H days away and I job transfer or restriction | (H + I) x 200,000 / hours |
| LTIR | H days away from work | H x 200,000 / hours |
Where the numbers come from on your 300 Log and 300A
The case counts are the column totals at the bottom of the OSHA 300 Log, and the 300A summary repeats them. Under 29 CFR 1904.32(b)(2) you total the columns of the log, entering zeros when there were no cases, and you enter the total hours worked by all employees covered by the log. Those two lines of the 300A are all the calculator needs. The BLS asks for hours actually worked, so vacation, sick leave and other paid time off stay out.
Is TRIR an OSHA requirement?
No. 29 CFR 1904.29(a) requires the OSHA 300 Log, the 300A summary and the 301 incident report, or equivalent forms. We searched the whole of Part 1904 in the eCFR (current to Oct 16, 2026) for “rate”, “incidence rate”, “TRIR”, “DART” and “lost time”: none of them appears.
The rates come from somewhere else. The formula is a statistical method of the BLS, used to publish national rates. TRIR and DART are what general contractors, owners and prequalification services put on their forms. LTIR is a company and industry measure with no definition in Part 1904, which is why the calculator says which column it counts.
What OSHA does require at year end is the summary itself: a company executive certifies the 300A after examining the log (29 CFR 1904.32(b)(3)), and it is posted from February 1 to April 30 (29 CFR 1904.32(b)(6)). The OSHA 300A tool builds that summary, and the ITA checker tells you whether it also goes to OSHA electronically.
Worked examples
A roofing contractor with 12 employees worked 25,000 hours last year and had one case with days away from work. TRIR = 1 x 200,000 / 25,000 = 8.00, and DART and LTIR are 8.00 too. The BLS 2024 rate for roofing contractors is 2.4. One case puts a small company far above it, which is why a single year of a small company says little on its own.
A fabricated metal shop with 180 employees worked 360,000 hours and logged nine cases: three with days away, two with restricted work and four others. TRIR = 9 x 200,000 / 360,000 = 5.00. DART = 5 x 200,000 / 360,000 = 2.78. LTIR = 3 x 200,000 / 360,000 = 1.67. The BLS 2024 rates for fabricated metal product manufacturing are 3.2 and 1.8.
TRIR by industry: BLS 2024 rates
Cases per 100 full-time workers in private industry, all establishment sizes, as published by the BLS Survey of Occupational Injuries and Illnesses for 2024. The calculator above looks up any of the 1,019 industries the BLS publishes from your NAICS code.
| Industry (NAICS) | Total recordable | DART | Days away from work |
|---|---|---|---|
| Private industry | 2.3 | 1.4 | 0.8 |
| Construction (23) | 2.2 | 1.3 | 0.9 |
| Construction of buildings (236) | 2.2 | 1.3 | 0.9 |
| Residential building construction (2361) | 2.5 | 1.4 | 1.0 |
| Nonresidential building construction (2362) | 1.9 | 1.2 | 0.8 |
| Heavy and civil engineering construction (237) | 1.8 | 1.0 | 0.6 |
| Specialty trade contractors (238) | 2.3 | 1.4 | 1.0 |
| Foundation, structure, and building exterior contractors (2381) | 2.6 | 1.8 | 1.2 |
| Poured concrete foundation and structure contractors (23811) | 2.8 | 2.0 | 1.3 |
| Roofing contractors (23816) | 2.4 | 1.7 | 1.1 |
| Electrical contractors and other wiring installation contractors (23821) | 1.8 | 1.1 | 0.7 |
| Plumbing, heating, and air-conditioning contractors (23822) | 3.0 | 1.7 | 1.1 |
| Drywall and insulation contractors (23831) | 2.9 | 2.0 | 1.2 |
| Painting and wall covering contractors (23832) | 1.6 | 1.1 | 1.0 |
| Manufacturing (31-33) | 2.7 | 1.7 | 0.8 |
| Food manufacturing (311) | 3.3 | 2.3 | 1.1 |
| Wood product manufacturing (321) | 4.2 | 2.7 | 1.5 |
| Fabricated metal product manufacturing (332) | 3.2 | 1.8 | 0.9 |
| Transportation equipment manufacturing (336) | 3.2 | 2.1 | 0.9 |
| Wholesale trade (42) | 2.2 | 1.6 | 0.9 |
| Truck transportation (484) | 2.9 | 2.2 | 1.6 |
| Warehousing and storage (493) | 4.8 | 4.1 | 1.5 |
| Services to buildings and dwellings (5617) | 2.6 | 1.8 | 1.3 |
| Landscaping services (56173) | 3.0 | 2.0 | 1.4 |
| Waste management and remediation services (562) | 3.5 | 2.7 | 1.6 |
| Automotive repair and maintenance (8111) | 1.9 | 1.1 | 0.9 |
Source: U.S. Bureau of Labor Statistics, Survey of Occupational Injuries and Illnesses, industry data for 2024 (data file of Jan 22, 2026), read on Oct 20, 2026. The BLS survey counts nonfatal cases; deaths are counted in a separate census. Full table: JSON file of the 1,019 industries.
What a rate can and can't tell you
A rate is only as good as the log behind it. A case left off the log lowers TRIR and is a recordkeeping problem of its own, and a small company's rate swings with every case. When a customer asks for three years of rates, send the three years and the hours behind them, so the reader sees the size of the sample. Compare with the BLS rate for your own NAICS code and year, never with another industry's.
Rates that keep themselves current, in HazComFast
This calculator gives you one year's rates from the numbers you type. In HazComFast the rates come from the log itself, for every establishment and jobsite, over the year and the last twelve months, with the BLS average for your NAICS code beside them.
Safety Performance: the rates, kept current
The Safety Performance screen keeps TRIR and DART for each establishment and jobsite, over the year and over the last twelve months, from the cases on the log and the hours entered by site and by month. TRIR counts columns H, I and J, the nonfatal cases the BLS counts, so the comparison with the BLS 2024 national rate for your NAICS code is like for like, and the BLS line used is shown. A lost-time frequency is there too, with its formula and a label that says it is neither an OSHA nor a BLS rate.
Day counts and privacy cases
When a case passes 180 “days away from work and/or days of job transfer or restriction”, the app stops at 180, the cap 29 CFR 1904.7(b)(3)(vii) allows. Cases still open on December 31 get an estimate before the 300A is generated, as 1904.7(b)(3)(ix) asks. A privacy concern case prints as “Privacy Case” in the name column, with the names on a separate confidential list (1904.29(b)(6)), and a worker who signs in reads their own 301, never a coworker's.
Forms in OSHA's layout, in English or Spanish
The 300, 301 and 300A print in the structure of OSHA's forms, in English or in Spanish: lettered columns A to M on the 300, questions 1 to 18 on the 301, and a certification block that's never split across pages. The 300 Log also exports as an Excel file in the 300's column layout, privacy cases masked. They are built as equivalent forms under 29 CFR 1904.29(a) and (b)(4) and 1904.32(b)(2)(iii); OSHA does not approve or certify any software.
Questions about TRIR, DART and LTIR
How do you calculate TRIR?
Add the cases in columns G, H, I and J of your OSHA 300 Log, multiply by 200,000 and divide by the total hours worked by all employees in the year. Eight recordable cases over 160,000 hours give 8 x 200,000 / 160,000 = 10.0. The method is the Bureau of Labor Statistics formula, (N/EH) x 200,000.
What is the difference between TRIR and DART?
TRIR counts every recordable case on the 300 Log. DART counts only the cases with days away from work (column H) or with job transfer or restriction (column I), so it tracks the more serious cases. Both use the same 200,000-hour base.
Does OSHA require you to calculate TRIR?
No. 29 CFR 1904.29(a) requires the OSHA 300 Log, the 300A summary and the 301, or equivalent forms, and Part 1904 contains no incidence rate. Customers, general contractors and prequalification services ask for TRIR and DART; OSHA asks for the forms.
What is LTIR, and is it an OSHA term?
LTIR, the lost-time incident rate, is an industry measure with no definition in Part 1904. This calculator counts the cases with days away from work, column H of the 300 Log, which are the cases the BLS publishes as its rate of cases involving days away from work. Some clients add deaths or define it their own way, so check the form you are filling in.
What is a good TRIR?
OSHA sets no target rate. The fair comparison is the BLS rate for your own industry and year. For 2024 the BLS published 2.3 for private industry as a whole and 2.2 for construction. Enter your NAICS code above to see the rate for your trade, then look at what drove your cases, since one establishment over one year is a small sample.
Do deaths count in TRIR?
It depends on whose definition you follow. Counting every line of the 300 Log includes column G. OSHA's optional rate page in its forms package also gives the total as columns H, I and J of the 300A, which leaves deaths out, and the BLS survey counts nonfatal cases only. When column G has a death, the calculator shows TRIR both ways and compares the rate without deaths with the BLS.
Why 200,000 hours?
It is the hours of 100 full-time workers in a year, at 40 hours a week for 50 weeks. Multiplying by 200,000 turns your count into cases per 100 full-time workers, so a company of 20 and a company of 2,000 can be compared on the same scale.
What hours do I use?
The total hours worked by all employees last year, the figure on your 300A. OSHA's worksheet in its forms package says to include salaried, hourly, part-time and seasonal workers and temporary workers you supervise day to day, and to leave out vacation, sick leave, holidays and other time not worked, even when it was paid. If you have no exact figure, the OSHA 300A tool on this site estimates it from headcount.
Sources and verification
- OSHA, Forms for Recording Work-Related Injuries and Illnesses (forms package, PDF of Aug 5, 2025)
- BLS, SOII industry series: method and definitions (is.txt)
- BLS, How To Compute Your Firm's Incidence Rate for Safety Management
- BLS, SOII industry data, 2024 (file of Jan 22, 2026)
- 29 CFR Part 1904, Recording and Reporting Occupational Injuries and Illnesses (eCFR)
- 29 CFR 1904.29, Forms
- 29 CFR 1904.32, Annual summary
Verified against the eCFR on Oct 20, 2026 (title 29 current to Oct 16, 2026) and against the BLS files read the same day. State Plans record injuries and illnesses the way federal OSHA does (29 CFR 1904.37(b)(1)). Not legal advice.
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