200,000-hour base · 29 CFR 1904.7 · 300A
TRIR, DART and DAFW — computed honestly
Three incidence rates, one denominator, and one rule we will not bend: with no hours worked there is no rate. A 0.00 in that box would claim a perfect safety record nobody has measured.
What each one measures
Same denominator, narrower numerators
All three are cases per 200,000 hours worked — 100 full-time employees at 40 hours a week for 50 weeks. Only the numerator changes.
TRIR
Total Recordable Incident Rate
(Total recordable cases × 200,000) ÷ hours worked
Every case on the 300 Log for the year — the broadest measure, and the one most often asked for in prequalification.
DART
Days Away, Restricted, or Transferred
(Cases with days away + cases with restriction or transfer × 200,000) ÷ hours worked
The subset of recordable cases severe enough to change what the employee could do. Always at or below TRIR.
DAFW
Days Away From Work
(Cases with days away from work × 200,000) ÷ hours worked
The narrowest of the three: cases where the employee lost at least one full calendar day.
Calculator
Work out your establishment's rates
Everything runs in your browser — nothing is sent anywhere. Leave a field blank and the rates it feeds say so.
Your establishment’s year
Enter the figures
Runs in your browser. Leave a box blank and the rates it feeds read “No data” — never a zero.
Actual hours worked in the year — not hours paid. Overtime counts; vacation, sick leave and holidays do not.
Every case entered on the 300 Log for the year (300A column G+H+I+J).
300A column H.
300A column I — restricted or transferred, but no days away.
TRIR
Total Recordable Incident Rate
No data
(total recordable cases × 200,000) ÷ hours worked
DART
Days Away, Restricted, or Transferred
No data
((days-away cases + restricted/transferred cases) × 200,000) ÷ hours worked
DAFW
Days Away From Work rate
No data
(days-away cases × 200,000) ÷ hours worked
Why “No data” and not 0.00
An incidence rate is cases per 200,000 hours worked. With no hours entered there is no denominator, so there is no rate. A 0.00 in that box would claim a perfect safety record you have not measured — which is exactly the number an auditor will ask you to substantiate.
Why a blank never becomes a zero
A rate is a ratio. Without hours worked there is no denominator, so there is no rate — and printing 0.00 does not represent that absence, it asserts something much stronger: that you worked measured hours and had no recordable cases.
This matters beyond tidiness. TRIR and DART travel outside the business — into prequalification questionnaires, insurance submissions and client audits. A zero you cannot substantiate with an hours figure is a number you will eventually be asked to defend.
Zero recordable cases across real hours worked is a legitimate and excellent result, and it renders as 0.00 here — you just have to enter the hours that make it true.
29 CFR 1904.7(b)(3) and (b)(4)
Counting the days
The numerators above count cases, but the 300 Log also records day counts — and the counting rules are specific.
(i) Do I count the day on which the injury occurred or the illness began? No, you begin counting days away on the day after the injury occurred or the illness began.
(iv) How do I count weekends, holidays, or other days the employee would not have worked anyway? You must count the number of calendar days the employee was unable to work as a result of the injury or illness, regardless of whether or not the employee was scheduled to work on those day(s). Weekend days, holidays, vacation days or other days off are included in the total number of days recorded if the employee would not have been able to work on those days because of a work-related injury or illness.
(xi) How do I count days of job transfer or restriction? You count days of job transfer or restriction in the same way you count days away from work, using § 1904.7(b)(3)(i) to (viii), above. The only difference is that, if you permanently assign the injured or ill employee to a job that has been modified or permanently changed in a manner that eliminates the routine functions the employee was restricted from performing, you may stop the day count when the modification or change is made permanent. You must count at least one day of restricted work or job transfer for such cases.
The 180-day cap · 1904.7(b)(3)
You may stop counting at 180 days
(vii) Is there a limit to the number of days away from work I must count? Yes, you may “cap” the total days away at 180 calendar days. You are not required to keep track of the number of calendar days away from work if the injury or illness resulted in more than 180 calendar days away from work and/or days of job transfer or restriction. In such a case, entering 180 in the total days away column will be considered adequate.
The cap applies to days away and to days of restriction or transfer, and it is a ceiling on the whole case rather than per calendar year. Once a case reaches 180 days you enter 180 and stop tracking. Note what the cap does not do: it does not close the case, and it does not affect the case counts in TRIR or DART — those count cases, not days.
Common questions
Straight answers, with the citation
- What is the formula for TRIR?
- TRIR = (total recordable cases × 200,000) ÷ total hours worked by all employees. The 200,000-hour base represents 100 full-time employees working 40 hours a week for 50 weeks, which is the basis OSHA and the Bureau of Labor Statistics publish against. With no hours worked there is no rate at all — not a rate of zero.
- What is the difference between TRIR and DART?
- TRIR counts every recordable case. DART counts only the subset of cases that involved days away from work, restricted work, or transfer to another job — so DART is always less than or equal to TRIR. DAFW narrows further, to cases with days away only.
- Do I have to count more than 180 days away from work?
- No. 29 CFR 1904.7(b)(3) states: "(vii) Is there a limit to the number of days away from work I must count? Yes, you may “cap” the total days away at 180 calendar days. You are not required to keep track of the number of calendar days away from work if the injury or illness resulted in more than 180 calendar days away from work and/or days of job transfer or restriction. In such a case, entering 180 in the total days away column will be considered adequate."
- Do I count the day of the injury as a day away?
- No. 29 CFR 1904.7(b)(3)(i) states: "(i) Do I count the day on which the injury occurred or the illness began? No, you begin counting days away on the day after the injury occurred or the illness began."
Not legal advice. This page republishes 29 CFR Part 1904 as published by the eCFR and explains it. The recordkeeping duty is the employer’s. Where the rule requires judgement, Job13 says so rather than guessing — run your own case through the free check.