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INCIDENT RATES · US METHOD

DART rate calculator

Calculate the days away, restricted or transferred case rate using DART cases and employee hours worked.

Your details

Count cases in OSHA 300 columns H + I, not days lost. Each case is counted once.
Use actual hours for the same workforce and period. Exclude paid time not worked.

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Your result Calculated locally

Your result, explained.Enter your readings and select Calculate.
Or try the example to see how it works.

This rate does not certify a workplace as safe. Use it alongside other safety indicators.

▶ New here? See a step-by-step example Open walkthrough

NEW TO THIS TOOL?

Three steps. One clear result.

  1. Count qualifying cases

    Use DART cases from OSHA 300 columns H + I. Count cases once, not days lost.

  2. Add matching hours

    Enter actual hours worked by the same workforce during the same period. Select Calculate.

  3. Read your rate

    The example gives 1.60 cases per 100 full-time equivalent workers. DART is not the same as TRIR.

ILLUSTRATIVE EXAMPLE · NOT YOUR DATA
STEP 1 OF 3 · Example records2 DART cases · 250,000 hours
Step 1 of 3

Want to try these numbers? Select “Try a filled example” below. Your own figures are only replaced when you select that button.

How the DART rate is calculated

DART means days away, restricted or transferred. Use the number of qualifying cases, rather than the sum of days. OSHA’s Field Operations Manual describes the numerator as OSHA 300 columns H + I.

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

The 200,000-hour basis represents 100 full-time equivalent workers working 40 hours per week for 50 weeks. Keep cases and hours aligned. Do not count a case twice because it had both time away and restricted duty.

TRIR uses the total recordable case count, so the two numerators are not interchangeable.

Worked example

2 DART cases and 250,000 hours worked:

(2 × 200,000) ÷ 250,000 = 1.60

The rate is 1.60 cases per 100 full-time equivalent workers. It is not a percentage or a benchmark.

Use the result in context

Small workforces and short periods can produce volatile rates. This tool does not decide recordability or meet reporting duties on your behalf. Compare matched periods and similar operations; evaluate additional leading and lagging indicators.

Local prototype: arithmetic checked. Professional review of scope and instructions remains part of the release process.

Common questions

Do I enter days lost or cases?

Enter the number of DART cases, not days. Use OSHA 300 columns H plus I, counting each case once.

What if there were no DART cases?

Enter 0 cases and the actual positive hours worked. The result is zero, which does not prove there are no workplace hazards.

Can I use monthly figures?

Use cases and hours for the same workforce and period. Keep the 200,000 constant and label your reporting period. Short periods can be volatile.

Is DART the same as TRIR?

No. TRIR includes the total recordable case count. DART uses the subset involving days away, restricted work or job transfer.

Original references

  1. OSHA Field Operations Manual, chapter 3 — DART numerator and incidence-rate calculation.
  2. OSHA recordkeeping forms — columns, records and hours worked.

References checked 1 November 2026. Independent tool, not agency-endorsed.

KEEP WORKING

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