Free tool
OSHA incidence rate calculator
TRIR and DART from your case counts and hours worked. Nothing is sent anywhere. The arithmetic runs in your browser.
Every case on the 300 Log for the year.
Days away, restricted, or transferred: columns H and I.
Actual hours, not scheduled. 100 full-time employees is roughly 200,000.
TRIR
0.00
Total recordable incidence rate
DART rate
0.00
Days away, restricted or transferred
How this is calculated
Both rates use OSHA’s formula: (N ÷ hours worked) × 200,000, where 200,000 is 100 full-time employees working 40 hours for 50 weeks. That constant is what makes a 40-person clinic comparable with a 4,000-person system.
TRIR counts every recordable case. DART counts only those with days away, restricted work or transfer. That is a subset, so it is always the lower of the two.
A worked example
A hospital whose employees worked 1,150,000 hours in the year recorded 21 cases on its 300 Log, 9 of them with days away, restricted work or a job transfer.
- TRIR: 21 × 200,000 ÷ 1,150,000 = 3.65
- DART rate: 9 × 200,000 ÷ 1,150,000 = 1.57
Both are rates per 100 full-time workers per year, which is what lets you compare a year of 1,150,000 hours with someone else's 200,000.
What counts as hours worked
Use the hours your employees actually worked, the same figure that goes on the 300A. OSHA's worksheet counts salaried, hourly, part-time and seasonal staff, and temporary workers you supervise day to day. It leaves out time not worked even when it is paid, such as vacation, sick leave and holidays. If you do not have actual hours, the 300A worksheet explains how to estimate them.
Where the numbers come from on your 300A
Total recordable cases is the sum of columns G, H, I and J: deaths, cases with days away from work, cases with job transfer or restriction, and other recordable cases. DART cases are columns H and I.
How healthcare compares
In 2023, private industry as a whole recorded 2.4 cases per 100 full-time workers, and health care and social assistance recorded 3.6 (BLS). Patient handling and sharps put healthcare above the average, so compare a hospital's rate with its own sector rather than with all industries.
Common mistakes
- Using scheduled hours instead of hours actually worked.
- Counting first-aid-only cases. A case that is not on the 300 Log is not in the rate.
- Leaving out privacy concern cases. They are recordable cases entered without a name, and they count.
- Dividing by headcount. The formula needs hours.
More on this: occupational health metrics that matter and how to complete OSHA Form 300A. The other free tool, Is it OSHA recordable?, decides whether a case belongs on the log in the first place.
Questions
What is the difference between TRIR and DART?
TRIR counts every recordable case. The DART rate counts only cases with days away from work, restricted work or a job transfer, so it is always the lower of the two.
Do privacy concern cases count toward the rate?
Yes. A privacy concern case is a recordable case entered without the employee's name, so it counts in TRIR, and in DART if it involved days away, restriction or transfer.
Can I calculate a rate for one department or one site?
Yes, using that department's or site's cases and the hours its employees worked. The arithmetic is the same.
Is anything I enter sent anywhere?
No. The calculation runs in your browser, and nothing is stored or sent.