Tools

OSHA incident rate calculator (TRIR and DART)

Calculate TRIR, DART rate, lost-time case rate and severity rate from your OSHA 300 log and hours worked, and compare them with an industry rate.

Runs entirely in your browser: nothing you enter is sent or stored by this site. Results are estimates for planning, not a quote or advice.

How to use it

You need a year of your OSHA 300 log and the hours from the 300A summary. The starting figures are examples.

  • Recordable cases. The total of columns G, H, I and J on the 300 log (deaths, days away, job transfer or restriction, and other recordable cases).
  • DART cases. Days away, restricted or transferred (DART): columns H plus I.
  • Cases with days away from work. Column H. This drives the lost-time case rate.
  • Total days away from work. Column K. This drives the severity rate.
  • Hours worked. Choose "I know total hours worked" and enter the total hours for all employees from the 300A. Or choose the estimate, then enter the average number of employees and average hours per employee, such as 2,000 for 40 hours over 50 weeks. Only the fields for your choice show.
  • Industry TRIR and DART (optional). Type in the rates for your industry from the BLS Survey of Occupational Injuries and Illnesses at bls.gov/iif.

If you are a small employer, you may be partially exempt from keeping the log, but customers and insurers can still ask for the same rates, and you can compute them from your own records of work-related injuries.

The math

Every rate has the same shape: cases × 200,000 ÷ hours worked. The constant 200,000 stands for 100 full-time workers at 40 hours a week for 50 weeks, so the result reads as cases per 100 full-time workers.

  • TRIR = recordable cases × 200,000 ÷ hours
  • DART rate = DART cases × 200,000 ÷ hours
  • Lost-time case rate = cases with days away × 200,000 ÷ hours
  • Severity rate = days away × 200,000 ÷ hours

Hypothetical: a shop logs 3 recordable cases, one of them a DART case that kept the employee home 9 days, over 180,000 hours. TRIR = 3 × 200,000 ÷ 180,000 = 3.33. DART rate = 1.11. Lost-time case rate = 1.11. Severity rate = 9 × 200,000 ÷ 180,000 = 10.0 days per 100 full-time workers.

A bar chart sets your TRIR next to the private-industry rate: the Bureau of Labor Statistics reported 2.3 total recordable cases per 100 full-time workers in private industry for 2024 (released January 22, 2026). If you enter an industry TRIR, the page says whether yours is at or below it and, if above, how many times it. Entering an industry DART adds a second pair of bars, with no verdict.

Assumptions and limits

  • Small numbers swing. With few hours, one case moves the rate sharply. On 40,000 hours, roughly 20 full-time workers, a single recordable case is worth 5.0 points of TRIR.
  • Only what you count. The tool does not decide whether a case is recordable. Use the 300 log instructions or your safety consultant.
  • Severity here means days away only. Restricted-duty days are not in this tool's severity rate, and other definitions exist, so ask what a prequalification form means before you copy the number.
  • One year at a time. Many contractor prequalification forms ask for three years of TRIR and DART and your experience mod. Run each year separately.
  • Benchmarks must match. The 2.3 figure covers all private industry. Your industry's rate, from the BLS tables for your NAICS code, is the fairer comparison, and rates differ by employer size.
  • Hours, not headcount. Include hours of part-time and seasonal staff. An hours estimate from headcount is only as good as your average.

Insurers and clients use these rates alongside your mod as a quick read on safety. A high rate is a prompt to look at causes and controls, not a verdict. See OSHA recordkeeping, injury rates and insurance, building a workplace safety program that cuts claims and the Experience mod (EMR) calculator.

Where the figures come from

Last reviewed October 10, 2026

Related guides

OSHA recordkeeping, injury rates and insurance Which injuries go on the OSHA 300 log, how TRIR and DART are calculated, and how underwriters, contract owners and your experience mod read the numbers. Building a workplace safety program that cuts claims How to build a written workplace safety program with OSHA's seven core elements and the hierarchy of controls, and what insurers and state credits look for. The experience modification rate (EMR) explained How the NCCI experience mod is calculated from payroll and losses, which policy years count, why frequency outweighs severity, and how to check your worksheet. Insurance loss control inspections: what to expect What an insurer's loss control inspection covers, the policy wording behind it, how to prepare, how to answer recommendations and what ignoring them can cost. Managing subcontractor insurance and certificates What to require from subcontractors, which endorsements to collect, how to verify comp and liability coverage, and what falls on you if a sub has none.

Terms used here

Total recordable incident rate (TRIR) A safety metric showing OSHA-recordable injuries and illnesses per 100 full-time workers in a year, calculated from case counts and hours worked. DART rate An OSHA incident rate counting injury and illness cases that caused days away from work, restricted duty or a job transfer, per 100 full-time workers. OSHA recordable injury A work-related injury or illness meeting OSHA's recording criteria, such as lost time, restricted duty or care beyond first aid, entered on the OSHA 300 log. Experience modification rate (EMR) A multiplier on workers' compensation premium comparing an employer's actual claim losses with the losses expected for its industry and size.

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