How to Calculate TRIR and DART Rates — Formulas, Examples & 2026 Industry Benchmarks

What Are TRIR and DART?

TRIR (Total Recordable Incident Rate)measures how many OSHA recordable injuries and illnesses occur per 100 full-time employees per year. It's the single most widely used safety performance metric in US industry — used by OSHA, insurance underwriters, general contractors, and corporate boards to assess safety performance.

DART (Days Away, Restricted, or Transfer Rate)is a subset of TRIR. It counts only the more serious cases — those that resulted in days away from work, job transfer, or restricted duty. DART tells you how many incidents were serious enough to impact your workforce's ability to work.

Both rates are normalized to 100 full-time employees using the 200,000-hour baseline, which allows fair comparison between facilities of different sizes.

The TRIR Formula — Step by Step

TRIR = (Number of Recordable Incidents × 200,000) ÷ Total Hours Worked

Where:

• Number of Recordable Incidents — total cases from your OSHA 300 log for the period (all columns: J + K + L + M)
• 200,000 — the normalizing constant (100 employees × 50 weeks × 40 hours)
• Total Hours Worked — actual hours worked by all employees including overtime; exclude vacation, sick leave, and holidays

The DART Formula — Step by Step

DART = (DART Cases × 200,000) ÷ Total Hours Worked

DART cases are those in Columns K and L of your OSHA 300 log:

• Column K — Cases with days away from work
• Column L — Cases with job transfer or restriction
• Column J (deaths) is NOT included in DART
• Column M (other recordable cases with no lost days) is NOT included in DART

Calculating Total Hours Worked Correctly

Hours worked is the most common calculation error. Here's exactly what to include and exclude:

If you don't track exact hours, OSHA allows you to estimate: multiply your average employee count by 2,000 hours (50 weeks × 40 hours) for a reasonable approximation for salaried workers. For hourly workers, pull from your payroll system — actual hours are more accurate.

2026 Industry Benchmark Rates

Use these BLS averages (most recent data) to benchmark your facility's performance. A rate below your industry average generally indicates a strong safety program. A rate significantly above average may attract OSHA targeted inspection attention.

TRIR vs DART — Key Differences

Common Calculation Mistakes

• Including non-work-related cases in the numerator — only cases that meet OSHA work-relatedness criteria count
• Using headcount instead of hours — the formula requires actual hours worked, not employee count alone
• Forgetting part-time and seasonal workers — their hours must be included
• Including Column J (fatalities) in DART — fatalities are NOT included in DART, only in TRIR
• Calculating over less than 12 months — for annual rates, always use the full calendar year
• Using 2,000 hours for all employees — hourly workers with overtime will have more; pull actual payroll data

How OSHA Uses Your TRIR

OSHA uses industry TRIR averages to identify high-hazard establishments for targeted inspections under the Site-Specific Targeting (SST) program. Establishments with TRIR significantly above the industry average are more likely to be selected for a programmed inspection — even without a complaint or incident trigger.

Additionally, many general contractors and large clients now require subcontractors and suppliers to submit TRIR and DART data as part of contractor prequalification. A high rate can cost you contracts worth far more than the cost of improving your safety program.

How Often Should You Calculate TRIR?

Annually for OSHA reporting purposes. But best-practice EHS programs track TRIR monthly on a rolling 12-month basis — this smooths out seasonal variation and lets you spot trends before they compound. If your rolling TRIR starts climbing in Q2, you want to know in Q2, not when you calculate the annual rate in January.