How to Calculate Your OSHA DART Rate Step by Step
DART rate = (number of 300A column H and I cases) × 200,000 ÷ total hours worked by all employees covered by the log.
What you are aiming for
DART rate = (number of 300A column H and I cases) × 200,000 ÷ total hours worked by all employees covered by the log. It counts cases with days away, restriction, or job transfer, not the days themselves, and the 2024 private-industry average was 1.4.
DART gets reported to leadership, but the raw inputs often live across payroll and case logs.
What you need before you start
Gather these first, and keep them with the record afterward:
- The payroll report used for hours worked, with the date it was pulled
- Adjustments: paid leave removed, supervised temporary workers added
- The pay periods and headcounts behind the annual average employees figure
- The rate calculation with the case counts it used
The rule behind the steps
OSHA incidence rates scale case counts to 200,000 hours, which is 100 full-time workers at 40 hours a week for 50 weeks. TRIR (also called TCIR) = total recordable cases (300A columns G + H + I + J) × 200,000 ÷ total hours worked. DART = (cases in columns H + I) × 200,000 ÷ total hours worked. The 300A itself asks for the annual average number of employees and the total hours worked by all employees covered by the log (29 CFR 1904.32(b)(2)). For comparison, the BLS private-industry averages for 2024 were a TRIR of 2.3 and a DART rate of 1.4.
Step by step
- Confirm each case's column (H, I, or neither).
- Count the H and I cases.
- Total the hours worked by covered employees.
- Multiply by 200,000 and divide by the hours.
- Keep the inputs next to the result.
Tip: Count days-away, restricted-work, and job-transfer cases, multiply by 200,000, and divide by hours worked.
Where this usually goes wrong
Teams sometimes count restricted days instead of cases with restricted outcomes. The DART rate counts each case once, however long it runs; the day totals in columns K and L are a separate measure.
The denominator does as much work as the numerator. One wrong hours figure moves every rate, and the same hours also go on the 300A and into the ITA submission. The fix is to document the method once (which payroll report, which exclusions, which estimates) and use the same hours for the 300A, the ITA, and every rate.
Analysts are measured on numbers leadership trusts, so document every input and assumption behind a rate or a total.
Special situations
- Short-term establishments and acquired locations can make hours worked messy.
- Small establishments swing sharply: one recordable case at 40,000 hours is a TRIR of 5.0.
A worked example
A site has 5 recordable cases: 2 in column H, 1 in column I, and 2 in column J, with 245,000 hours worked. DART = 3 × 200,000 ÷ 245,000 = 2.45. The restricted case had 40 restricted days, but that does not change the DART rate, which counts the case once.
Use the DART rate calculator to check your own H and I case totals against hours worked, with the formula shown beside the result.
How it affects the rest of your records
Hours worked and average employees appear on the posted 300A and in the ITA submission, so a figure that is wrong for the rate is also wrong on two regulatory documents.
Where 300log helps
300log totals each establishment's columns as cases are recorded and keeps average employees and hours worked with the 300A, so the rate, the posted summary, and the ITA submission all use the same numbers.
For a quick answer without an account, use the free rate calculator.
Frequently asked questions
Does hours worked include salaried staff?
Yes, if they are covered by the log. Use actual hours where you have them and a reasonable, documented estimate for exempt staff.
What is the formula for TRIR?
TRIR = total recordable cases × 200,000 ÷ total hours worked. The case count is the sum of 300A columns G, H, I, and J.
What counts toward DART?
Cases with days away from work (column H) plus cases with job transfer or restriction (column I). It counts cases, not days.
Is there an official severity rate?
No. OSHA and BLS publish no official severity rate. Some teams track a day count rate, (days away + days restricted) × 200,000 ÷ hours, from an archived OSHA worksheet, but it has no BLS benchmark.
Sources
Primary regulation and agency guidance this article relies on.
- [1]29 CFR 1904.32: Annual summary certification and postingOccupational Safety and Health Administration · osha.gov(opens in a new tab)
- [2]29 CFR 1904.7: General recording criteriaOccupational Safety and Health Administration · osha.gov(opens in a new tab)
- [3]29 CFR 1904.30: Multiple business establishmentsOccupational Safety and Health Administration · osha.gov(opens in a new tab)
Written and reviewed by the 300log Editorial Team. Guidance, not legal advice: confirm edge cases with OSHA or counsel.