OSHA Incident Rate Formula: TCIR, DART, and Benchmarks

The OSHA incident rate formula is the same for both common measures: multiply the number of qualifying cases by 200,000, then divide by the total hours worked by all employees during the year. The Total Case Incident Rate (TCIR) counts every recordable injury and illness on your OSHA 300 log. The Days Away, Restricted, or Transferred (DART) rate counts only the subset of cases that kept someone off the job, restricted their duties, or moved them to a different position. The 200,000 constant represents what 100 full-time employees would work in a year at 40 hours per week for 50 weeks, which lets a 50-person shop and a 5,000-person plant be compared on the same scale.¹

Which Cases Belong in the Numerator

Getting the case count right is where most calculation errors start. A work-related injury or illness is recordable if it results in any of these outcomes: death, one or more days away from work, restricted duties or a job transfer, medical treatment beyond first aid, loss of consciousness, or a significant condition diagnosed by a physician or other licensed healthcare provider. That last category catches things people often miss. A fractured bone, punctured eardrum, cancer diagnosis, or chronic irreversible disease is recordable at the time of diagnosis even if the employee never misses a day.²

Where First Aid Ends and Medical Treatment Begins

The line between first aid and medical treatment decides whether many minor cases enter the log at all. OSHA’s first aid list includes wound cleaning, bandaging, tetanus shots, hot or cold therapy, non-rigid wraps and elastic bandages, eye patches, draining a blister, and using non-prescription medications at nonprescription strength. Cases treated only with those measures are not recordable. Once treatment crosses into prescription medications at prescription strength, sutures, rigid immobilization devices, or physical therapy, it qualifies as medical treatment and the case becomes recordable.²

Temporary Workers and Remote Workers

A case belongs on one employer’s log, not both. For temporary staffing arrangements, the employer who supervises the day-to-day details, methods, and processes records the injury, which usually means the host employer rather than the staffing agency.³ For employees working from home, an injury is recordable only if it happens while the employee is performing work for pay and is directly related to the work itself, not to the home environment. Dropping a box of work documents on your foot counts. Tripping over the family dog while heading to a work call does not.⁴

Calculating TCIR

The TCIR formula uses every recordable case on the 300 log:

TCIR = (Number of recordable injuries and illnesses × 200,000) ÷ Total hours worked by all employees

Say your company had 8 recordable cases last year and your employees worked a combined 400,000 hours. The math: (8 × 200,000) ÷ 400,000 = 4.0. For every 100 full-time employees working a full year, your workplace averaged four recordable injuries or illnesses.¹

Calculating DART

DART uses the same structure but narrows the numerator to cases that resulted in at least one day away from work, restricted duties, or a job transfer:

DART = (Number of DART cases × 200,000) ÷ Total hours worked by all employees

Using the same company: if 3 of those 8 recordable cases involved days away, restricted work, or a transfer, the DART rate is (3 × 200,000) ÷ 400,000 = 1.5. The other 5 cases, which involved only medical treatment beyond first aid or loss of consciousness without any work modification, don’t count toward DART.

What Restricted Work and Job Transfer Mean

A case counts as restricted work when the employee can’t perform one or more routine job functions, or can’t work a full scheduled shift, because of the work-related injury or illness. Physician-recommended restrictions count too, even if the employer would have let the employee keep working normally. A job transfer means the employee moves to a different position entirely. Either scenario pushes the case into the DART numerator, whether or not the employee ever missed a full day.⁵

Getting the Hours-Worked Denominator Right

The denominator is the actual hours worked by every employee on the payroll: full-time, part-time, temporary, and seasonal staff all count. Exclude vacation, sick leave, holidays, and any other paid but non-working hours. The goal is to reflect hours during which employees were actually exposed to workplace hazards.⁶

Salaried employees who don’t track hours can be estimated. A common approach is to multiply the number of salaried employees by the standard 2,000-hour work year (40 hours × 50 weeks). OSHA doesn’t require a sophisticated timekeeping system, just a defensible method. Sole proprietors, partners, and family members on family farms aren’t counted as employees for this calculation.⁶

Comparing Your Rates to Industry Benchmarks

A rate on its own doesn’t tell you much. The Bureau of Labor Statistics publishes incidence rates by detailed industry classification each year, covering total recordable cases, DART cases, and days-away-from-work cases by industry and establishment size.⁷ The 2024 private-industry average TCIR was 2.3 per 100 full-time equivalent workers.⁸ Averages vary sharply by sector. Construction, manufacturing, and warehousing tend to run higher; finance and professional services run well below. Compare against your own NAICS code rather than the overall average.

Why Your Rate Matters Beyond the Math

OSHA uses the data submitted through the Injury Tracking Application to decide who gets inspected. Under the Site-Specific Targeting program, establishments with 20 or more employees can be selected based on high injury and illness rates, rates that have trended upward over a multi-year window, or rates that fall suspiciously far below industry averages, which OSHA treats as a possible sign of underreporting. Failing to submit 300A data at all is itself a selection criterion.⁹ A high rate doesn’t automatically prove a safety violation, but it puts the establishment on OSHA’s radar for a comprehensive inspection.¹⁰

Your incident history also drives insurance cost through the Experience Modification Rate (EMR), which insurers calculate from claims over a rolling multi-year period. An EMR below 1.0 earns a premium discount; an EMR above 1.0 means a surcharge, sometimes 25 to 50 percent above what a company with a lower EMR would pay. Frequent small claims tend to raise the EMR more than a single large loss, because insurers read a pattern of incidents as a stronger predictor of future losses.

A Note on Older Metrics

References to the LWDII rate (Lost Workday Injury and Illness) or DAFWII rate (Days Away From Work Injury and Illness) show up in older documents. Those are predecessors. DART is the current standard because it captures restricted-duty and job-transfer cases that the older DAFWII metric missed.¹¹

1
Occupational Safety and Health Administration. Clarification on How the Formula Is Used by OSHA to Calculate Incident Rates
2
eCFR. 29 CFR 1904.7 – General Recording Criteria
3
Occupational Safety and Health Administration. Temporary Worker Initiative Injury and Illness Recordkeeping Requirements
4
Occupational Safety and Health Administration. Determining Work-Relatedness for Injuries in the Home When Telecommuting
5
Occupational Safety and Health Administration. 1904.7 – General Recording Criteria
6
Occupational Safety and Health Administration. Recordkeeping – Detailed Guidance for OSHA’s Injury and Illness Recordkeeping
7
U.S. Bureau of Labor Statistics. Industry Injury and Illness Data
8
U.S. Bureau of Labor Statistics. Employer-Reported Workplace Injuries and Illnesses – 2024
9
Occupational Safety and Health Administration. US Department of Labor Updates Inspection Program
10
Occupational Safety and Health Administration. OSHA Inspections
11
Occupational Safety and Health Administration. Site-Specific Targeting 2004 (SST-04)