12-Month Rolling Total Incident Rate (TRIR) Calculator
Calculated 12-Month Rolling TRIR:
What is a 12-Month Rolling Total Incident Rate?
The Total Recordable Incident Rate (TRIR) is a standard mathematical formula used by OSHA (Occupational Safety and Health Administration) to evaluate a company's safety performance. A 12-month rolling calculation provides a dynamic view of safety by looking at the most recent year of data, updated every month.
Unlike a calendar-year calculation, which resets every January, the rolling TRIR adds the current month's data and removes the data from 13 months ago. This ensures that safety managers are always looking at a full year of performance at any given time.
The TRIR Formula
The standard OSHA calculation is as follows:
The number 200,000 represents the base for 100 full-time equivalent workers (working 40 hours per week, 50 weeks per year).
Why Monitoring Rolling TRIR Matters
- Trend Analysis: It helps identify if safety is improving or declining in real-time.
- Contractor Prequalification: Many clients require a TRIR below a certain threshold (usually 3.0 or lower) to bid on projects.
- Internal Benchmarking: Compare different departments or sites using a standardized metric.
- Insurance Premiums: Higher incident rates often lead to higher workers' compensation costs.
Typical TRIR Benchmarks
| TRIR Range | Safety Standing | Action Required |
|---|---|---|
| 0.0 – 1.0 | Excellent | Maintain current safety culture. |
| 1.1 – 3.0 | Good/Average | Continue audits and training. |
| 3.1 – 5.0 | Below Average | Review safety protocols and PPE usage. |
| Over 5.0 | Poor | Immediate safety stand-down and systemic review. |
Example Calculation
If your facility had 4 recordable incidents in the last 12 months and your team worked a total of 450,000 hours, the calculation would be:
(4 x 200,000) / 450,000 = 1.78
This score of 1.78 suggests a strong safety program compared to many industrial averages.