The DART rate counts the injuries serious enough to keep a worker off the job or on restricted duties, per 100 full-time workers a year. This calculator works it out with TRIR, DAFW, DJTR and the severity rate, for one year or several, and compares it with Alberta and the US averages.
The formulas
- DART = (days-away + restricted or transferred cases) × 200,000 ÷ hours worked
- TRIR = all recordable cases × 200,000 ÷ hours worked
- DAFW = days-away cases × 200,000 ÷ hours worked
- DJTR = restricted or transferred cases × 200,000 ÷ hours worked
- Severity rate = days lost × 200,000 ÷ hours worked
Count each case once, in its most serious column: a case with days away and restricted duty is a days-away case.
Alberta employers don't keep an OSHA log, but prequalification programs such as ISNetworld, Avetta and ComplyWorks often ask for DART anyway. Count your lost-time claims as days-away cases and your modified-work claims as restricted cases, and the result lines up with Alberta's disabling injury rate.
Reading the trend
A single case can double a small company's rate, so one year says little. Enter three to five years to see the trend, and use the case budget to see how many cases next year's target leaves room for. For TRIF and lost-time frequency on other bases, use the TRIF calculator, and see the Canadian injury statistics for national numbers.
Sources: US Bureau of Labor Statistics, Survey of Occupational Injuries and Illnesses, 2024 (DART 1.4, total recordable 2.3, private industry); Government of Alberta, Workplace injury, illness and fatality statistics, provincial summary 2024 (disabling injury rate 2.42, lost-time claim rate 1.35).
Frequently asked questions
- How do you calculate a DART rate?
- DART rate = (days-away cases + restricted or transferred cases) × 200,000 ÷ total hours worked. 200,000 hours is 100 full-time workers for a year, so the rate is cases per 100 workers. For example, 3 DART cases in 240,000 hours is a DART rate of 2.5.
- What is a good DART rate?
- It depends on the industry. The US private-industry average was 1.4 in 2024 (BLS), and construction and heavy industry run higher. Compare with your own industry and, more usefully, with your own last three to five years: a falling trend is what clients and auditors look for.
- What is the difference between DART and TRIR?
- TRIR counts every recordable case, including medical treatment with no time lost. DART counts only the more serious ones: cases with days away from work, or restricted duties or a transfer to another job. DART is always the same as or lower than TRIR.
- Is there a DART rate in Canada?
- Not by that name. In Alberta, the disabling injury rate counts lost-time plus modified-work claims per 100 person-years, the same cases on the same base, so it is the Canadian equivalent: 2.42 for Alberta in 2024. The lost-time claim rate (1.35 in 2024) matches the DAFW rate. Alberta counts accepted WCB claims, not OSHA recordables, so the numbers are close but not identical.
- What is DAFW?
- DAFW (days away from work) counts only the cases where the worker missed work after the day of the injury: DAFW rate = days-away cases × 200,000 ÷ hours. It is the US equivalent of a lost-time injury frequency.
