DART Rate Calculator - OSHA Incident Rate

Calculate OSHA DART rate from days-away, restricted, or transfer cases and hours worked. Benchmark workplace injury incidence before you report.

Enter DART cases and total hours worked to compute the OSHA incidence rate per 100 full-time employees.

DART rate = (DART cases × 200,000) / hours worked

DART Cases

Hours Worked

About the OSHA DART rate calculator

DART stands for Days Away, Restricted, or Transferred. OSHA uses the DART rate to describe how often recordable injuries and illnesses cause an employee to miss work, work under restrictions, or move to another job. Safety managers, insurers, and procurement teams compare DART rates across sites and contractors because the number is normalized to 100 full-time workers. The DART rate calculator applies the same incidence formula OSHA publishes, so a small plant and a large warehouse can be compared on one scale. The formula is DART rate = (DART cases × 200,000) / hours worked. The 200,000-hour base is 100 employees × 40 hours × 50 weeks. Four DART cases in 200,000 hours produce a rate of 4.00 — four cases per 100 full-time workers in a year. Two cases in 400,000 hours produce 1.00. Eight cases in 160,000 hours produce 10.00, a high reading that often appears in small crews where a handful of cases swing the rate. Count only cases that meet OSHA’s DART definition on the OSHA 300 log: days away from work, restricted duty, or job transfer. Do not mix in first-aid-only events or cases that are recordable but involve no lost or restricted time (those belong in the total recordable incident rate, TRIR). Hours worked should be actual hours, including overtime, and should exclude leave, vacation, and other hours not worked. Temporary labor hours generally belong in the hours total if those workers’ cases are also in the case count. Industry benchmarks vary. Construction and manufacturing typically run higher than office environments. A contractor bid, an experience-mod discussion with an insurer, or an OSHA inspection file may all ask for the current DART rate. Use the same 12-month window you report on the OSHA 300A summary unless you are tracking a shorter internal period. Mid-year rates are noisier because the hours base is smaller. The incidence rate is not a probability that any one person will be hurt, and it is not a legal determination of fault. Case classification errors, missing contractor hours, and multi-establishment rollups are the usual reasons two people compute different DART rates from “the same” year. Recalculate when a case is reclassified or hours are restated, and keep the case list that supports the count. Used consistently, the DART rate calculator turns log entries into a benchmark you can defend.

OSHA DART rate examples

Each example uses (cases × 200,000) ÷ hours worked, the OSHA incidence formula.

Inputs	DART rate	Note
4 DART cases; 200,000 hours	4.00	Matches 4 cases per 100 full-time employees in a standard year.
2 DART cases; 400,000 hours	1.00	A larger hours base halves the incidence rate for the same case type.
8 DART cases; 160,000 hours	10.00	Smaller sites show higher rates when a few cases hit a thin hours base.

How to calculate OSHA DART rate

Count DART cases on the OSHA 300 log for the period: days away, restricted duty, or transfer.
Enter total hours actually worked in the same period, including overtime and excluding leave.
Select Calculate DART Rate to see cases per 100 full-time employees.
Compare the rate with your prior year, your industry, or a contractor requirement.

DART rate FAQ

What does DART mean in OSHA reporting?

DART means Days Away, Restricted, or Transferred. It counts recordable injuries and illnesses that keep someone off work, on restricted duty, or in a different job, not every first-aid event.

Why does the formula use 200,000 hours?

200,000 hours is OSHA’s base for 100 full-time employees working 40 hours a week for 50 weeks. Multiplying cases by that base, then dividing by hours worked, produces a rate per 100 FTE.

How is DART different from TRIR?

TRIR includes all OSHA recordable cases. DART is the subset that involve days away, restriction, or transfer. TRIR is always at least as high as DART for the same hours base.

Do I include contractor hours and cases?

Include them only when both the cases and the hours belong to the establishment you are measuring. Mixing contractor cases with host-employer hours, or the reverse, distorts the rate.

What is a good DART rate?

It depends on industry and size. Compare against Bureau of Labor Statistics incidence tables for your NAICS code and against your own trend. A falling rate with stable case definitions is more informative than a single-year snapshot.