DART Rate Calculator

Compute your OSHA DART rate — cases involving Days Away, Restriction, or Transfer per 200,000 hours worked — and compare it against a benchmark and the prior period.

Quick Facts

Formula
DART Rate = (Cases x 200,000) / Hours worked
Cases with days away, restriction, or transfer, per 200,000 hours worked — OSHA's standard incidence-rate base.
200,000-hour base
100 FTE x 40 hrs/wk x 50 wks
The same base OSHA uses for the Total Recordable Incident Rate (TRIR), so results are comparable across employer sizes.

Your Results

Calculated
DART rate
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Cases per 200,000 hours worked
Vs. prior period
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Change from your prior-period rate
Vs. industry benchmark
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Difference from the benchmark rate
Workforce scale
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Full-time-equivalent employees implied by hours

Ready

Enter DART cases, hours worked, and comparison rates, then press Calculate.

How the DART Rate Calculator works

DART stands for Days Away, Restricted, or Transferred. It is the OSHA-defined injury and illness rate that employers, insurers, and safety teams use to track how often work causes an employee to miss a day of work, get placed on restricted duty, or get transferred to a different job. It is a subset of the broader Total Recordable Incident Rate (TRIR) — every DART case is recordable, but not every recordable case is a DART case.

The formula

The calculator uses OSHA's standard incidence-rate formula:

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

The 200,000 figure is not arbitrary — it represents 100 full-time employees working 40 hours a week for 50 weeks a year (100 × 40 × 50 = 200,000 hours). Using it as the base means the result reads directly as "DART cases per 100 full-time workers," which lets you compare a 20-person shop and a 2,000-person plant on equal footing.

Worked example

Suppose a facility recorded 6 DART cases and its workforce logged 200,000 total hours during the year. The rate is (6 × 200,000) / 200,000 = 6.0. If instead that same facility logged 400,000 hours (twice the exposure) with the same 6 cases, the rate would be (6 × 200,000) / 400,000 = 3.0 — half as high, because the cases are spread across twice as many hours of work.

What counts as a DART case

  • Days away: the employee could not work at all for one or more days beyond the day of the incident.
  • Job restriction: the employee returned to work but could not perform their normal job duties for a period.
  • Job transfer: the employee was moved to a different job because of the injury or illness.

Recordable cases that involved only medical treatment beyond first aid — with no days away, restriction, or transfer — are excluded from DART but still count toward the broader TRIR.

Why total hours worked, not headcount

The denominator is total hours actually worked by all employees during the period, not a simple employee count. This matters because it automatically adjusts for part-time staff, overtime, seasonal hiring, and mid-year turnover — a site running heavy overtime has more exposure hours (and a lower rate for the same case count) than the same headcount working standard hours.

Reading your result

This calculator has no built-in "correct" target because acceptable DART rates vary enormously by industry — a warehouse and an office have very different baseline exposure. Instead, enter your own comparison points: a prior-period rate to see your trend, and a benchmark rate (such as your NAICS industry average from the Bureau of Labor Statistics, or an internal target) to see how far above or below it you sit. The calculator reports both differences in points and in percentage terms.

Frequently Asked Questions

How is the DART rate calculated?
DART Rate = (Number of DART cases x 200,000) / Total hours worked by all employees. A DART case is an OSHA-recordable injury or illness that resulted in Days Away from work, job Restriction, or job Transfer. The 200,000 figure is OSHA's standard base, equal to 100 full-time employees working 40 hours a week for 50 weeks a year, so the result reads as cases per 100 full-time workers.
What counts as a DART case?
A DART case is any OSHA-recordable work-related injury or illness where the employee missed at least one full day of work, was placed on job restriction, or was transferred to a different job, beyond the day of the incident. It excludes recordable cases that involved only medical treatment beyond first aid with no days away, restriction, or transfer.
What is a good DART rate?
There is no universal target because DART rates vary widely by industry, and this calculator does not supply industry averages. Enter your own benchmark, such as your NAICS industry average from the Bureau of Labor Statistics or your prior-year internal rate, and the calculator reports how far your current rate sits above or below it.
Why does total hours worked matter so much?
The DART rate normalizes case counts by exposure. Ten cases at a small site with 100,000 hours worked is a much higher rate than ten cases at a large site with 2,000,000 hours worked, even though the case count is identical. Using total hours worked (not headcount) accounts for part-time staff, overtime, and seasonal swings in the workforce.

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