Osha Injury Rate Calculation

OSHA Incident Rate Calculator (TRIR & DART)

Quickly calculate your organization's Total Recordable Incident Rate and DART Rate for safety compliance.

Total hours worked by all employees during the period (usually one year).

Cases from the OSHA 300 Log (Columns G, H, I, and J).

Cases involving time away from work or restricted duties (Columns H and I).

Your Safety Performance Results

TRIR Rate

0.00

Recordable Incidents

DART Rate

0.00

Restricted/Transfer Cases

function calculateOshaRates() { var hours = parseFloat(document.getElementById('osha_hours').value); var incidents = parseFloat(document.getElementById('osha_incidents').value); var dart = parseFloat(document.getElementById('osha_dart').value); var resultsDiv = document.getElementById('osha_results'); if (isNaN(hours) || hours <= 0) { alert('Please enter the total number of employee hours worked.'); return; } if (isNaN(incidents) || incidents < 0) { incidents = 0; } if (isNaN(dart) || dart < 0) { dart = 0; } // OSHA Formula: (Number of Incidents * 200,000) / Total hours worked var trir = (incidents * 200000) / hours; var dartRate = (dart * 200000) / hours; document.getElementById('trir_value').innerText = trir.toFixed(2); document.getElementById('dart_value').innerText = dartRate.toFixed(2); var summary = "For every 100 full-time employees working a full year, your organization experiences approximately " + trir.toFixed(2) + " recordable incidents and " + dartRate.toFixed(2) + " cases resulting in days away or restricted duty."; document.getElementById('osha_summary').innerHTML = summary; resultsDiv.style.display = 'block'; resultsDiv.scrollIntoView({ behavior: 'smooth', block: 'nearest' }); }

Understanding OSHA Injury Rate Calculations

OSHA (Occupational Safety and Health Administration) uses standardized incident rates to evaluate a company's safety performance compared to national averages in specific industries. These metrics are crucial for regulatory compliance and identifying areas for safety improvement.

Total Recordable Incident Rate (TRIR)

TRIR is the most common safety metric. It represents the number of work-related injuries and illnesses per 100 full-time employees. Companies with high TRIR scores may face increased scrutiny from OSHA and higher insurance premiums.

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

Days Away, Restricted, or Transferred (DART) Rate

The DART rate focuses specifically on more severe incidents—those that resulted in an employee spending time away from work, performing restricted duties, or being transferred to another job due to an injury or illness.

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

Why the 200,000 Factor?

The number 200,000 represents the equivalent of 100 employees working 40 hours per week, 50 weeks per year. This standardization allows for an "apples-to-apples" comparison between small shops and massive corporations.

Example Calculation

Imagine a manufacturing plant with the following data for one year:

• Total Hours Worked: 450,000
• Total Recordable Incidents: 8
• Total DART Cases: 3

Using our calculator, the TRIR would be 3.56 ((8 × 200,000) / 450,000) and the DART Rate would be 1.33 ((3 × 200,000) / 450,000).

Who Needs to Record These Rates?

Most employers with more than 10 employees are required to keep OSHA injury and illness records. While certain low-hazard industries are exempt from routine recordkeeping, all employers must report any work-related fatality within 8 hours and any work-related inpatient hospitalization, amputation, or loss of an eye within 24 hours.

💡 Pro Safety Tip

Regularly calculating your DART and TRIR rates (monthly or quarterly) can help you spot trends before they become major liabilities. Don't wait until your annual OSHA 300A summary is due to review your safety data!