Osha Calculation of Injury Rate

OSHA Injury Rate Calculator (TRIR & DART)

Calculate your Total Recordable Incident Rate and Days Away, Restricted or Transferred rate for compliance and safety benchmarking.

From OSHA Form 300 (Total cases in columns G, H, I, and J)

Total cases with days away, restricted work, or job transfer (Columns H and I)

Total actual hours worked by all employees during the period

Safety Performance Results

Total Recordable Incident Rate (TRIR):

0.00

DART Rate:

0.00

Understanding OSHA Injury Rate Calculations

In the United States, the Occupational Safety and Health Administration (OSHA) uses standardized formulas to help businesses compare their safety performance against industry averages. These metrics provide a snapshot of how many workplace injuries occur relative to the size of the workforce.

1. Total Recordable Incident Rate (TRIR)

TRIR is the most common safety metric. It includes all work-related injuries and illnesses that require medical treatment beyond first aid, as well as those involving loss of consciousness, restricted work, or days away from work.

The Formula:
(Number of Recordable Cases × 200,000) / Total Employee Hours Worked

The "200,000" figure represents the number of hours 100 full-time employees would work in a year (100 employees × 40 hours/week × 50 weeks/year).

2. DART Rate

The DART (Days Away, Restricted, or Transferred) rate is a more specific metric that tracks the severity of injuries. It focuses only on incidents that forced an employee to take time off, perform light duty, or move to a different job function.

The Formula:
(Number of DART Cases × 200,000) / Total Employee Hours Worked

Example Calculation

Imagine a manufacturing plant with 120 employees who worked a combined total of 240,000 hours last year. During that time, they had 6 recordable injuries, 3 of which resulted in days away from work or job restrictions.

• TRIR Calculation: (6 × 200,000) / 240,000 = 5.0
• DART Calculation: (3 × 200,000) / 240,000 = 2.5

Why These Rates Matter

Maintaining low TRIR and DART rates is critical for several reasons:

• Compliance: High rates may trigger OSHA inspections or audits.
• Insurance: Lower rates often lead to lower Workers' Compensation insurance premiums.
• Bidding: Many government and private contracts require companies to disclose their TRIR; high rates can disqualify you from bidding.
• Safety Culture: These metrics help management identify trends and implement corrective actions to protect workers.

function calculateOshaRates() { var totalInjuries = parseFloat(document.getElementById("totalInjuries").value); var dartCases = parseFloat(document.getElementById("dartCases").value); var totalHours = parseFloat(document.getElementById("totalHours").value); var resultDiv = document.getElementById("oshaResults"); var trirDisplay = document.getElementById("trirValue"); var dartDisplay = document.getElementById("dartValue"); var summaryDisplay = document.getElementById("oshaSummary"); // Basic validation if (isNaN(totalInjuries) || isNaN(totalHours) || totalHours totalInjuries) { alert("DART cases cannot be greater than the total number of injuries."); return; } // Calculations var trir = (totalInjuries * 200000) / totalHours; var dart = (dartCases * 200000) / totalHours; // Display Results trirDisplay.innerHTML = trir.toFixed(2); dartDisplay.innerHTML = dart.toFixed(2); resultDiv.style.display = "block"; // Generate Summary Text var summary = "Your company's TRIR of " + trir.toFixed(2) + " means that for every 100 full-time employees, approximately " + trir.toFixed(1) + " recordable injuries occurred over the course of a year."; if (trir > 3.0) { summary += " This rate may be considered high depending on your industry average. Consider reviewing safety protocols."; } else { summary += " This reflects your current safety performance based on the hours worked."; } summaryDisplay.innerHTML = summary; // Scroll to results smoothly resultDiv.scrollIntoView({ behavior: 'smooth', block: 'nearest' }); }