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TRIR and DART rate calculator

Both rates are the same piece of arithmetic: take the number of cases, multiply by 200,000, and divide by the hours your employees actually worked. TRIR counts every recordable case on the OSHA 300 log. DART counts only the cases that cost days away from work, restricted duty, or a job transfer. Dividing by the 200,000 hour base is what turns both into a rate per 100 full-time employees, so a 10-person site and a 900-person site can be read on the same scale.

Every case on the log for the period.

OSHA 300 columns H + I + J

The subset with days away from work, restricted duty, or a job transfer.

OSHA 300 columns H + I

Hours actually worked over the same period. Not scheduled hours, and not vacation or sick leave.

Fill in all three numbers to see a rate.

How it is calculated

OSHA states the formula as: (Number of injuries and illnesses x 200,000) / Employee hours worked = Incidence rate. The same formula produces both rates; only the case count changes.

  • TRIR, which OSHA's own data pages call the Total Case Rate, counts every case on the OSHA 300 log: columns H, I, and J together.
  • DART counts columns H and I only: days away from work, and restricted work or job transfer.
  • 200,000 is the number of hours 100 employees working 40 hours a week, 50 weeks a year would work. That is why a rate reads as cases per 100 full-time employees per year.

Hours worked means hours actually worked. Vacation, sick leave, and holidays are not hours worked, and including them understates the rate.

Source: OSHA, Establishment Specific Injury and Illness Data, Rate Calculation. Read 29 August 2026. If OSHA changes the page, this one changes with it.

Source: OSHA letter of interpretation, 23 August 2016, on the 200,000 hour base. Read 29 August 2026. If OSHA changes the page, this one changes with it.

There are no industry averages on this page on purpose. BLS publishes and revises those every year, and a benchmark copied here would go stale without anyone noticing. Compare your rate against your industry using the BLS injury and illness incidence rate comparison tool. This calculator is informational and does not replace your recordkeeping obligations under 29 CFR Part 1904.

Write the procedure behind the number

This tool is free and stays free. If you want the written SOPs to go with it, answer the facility questionnaire once and every template comes back with your equipment, your job titles, and your sign-off sheet attached.

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