How to Roll Up TRIR and Incident Trends Across Projects
Reviewed by Rivkor safety content team · Last reviewed: 2026-10-23 · Updated for small-business EHS programs · Not legal advice
Quick answer
To roll up TRIR across projects, do not average the project rates. Add the recordable cases from every project, add the hours worked on every project, and calculate once: total cases × 200,000 ÷ total hours. One practical option is to review that company-wide number monthly with a rolling 12-month view, and keep each project's rate beside it.
If you run several jobs, sites, or crews, someone eventually asks for one safety number for the whole company. Owners ask for it, insurers ask for it, and prequalification forms ask for it. Getting that number wrong is easy, and a wrong TRIR can make you look safer or riskier than you are. This guide shows the correct roll-up, how to keep project-level detail, and how to build a trend you can act on.
Start with the formula
TRIR (Total Recordable Incident Rate) is the number of OSHA-recordable cases per 100 full-time workers per year: cases × 200,000 ÷ hours worked. If the terms are new, read what TRIR means and the related TCIR and RIR definitions, which use the same math under different names.
The common mistake: averaging project rates
Suppose three projects ran during the year:
| Project | Recordable cases | Hours worked | Project TRIR |
|---|---|---|---|
| Project A | 2 | 80,000 | 5.00 |
| Project B | 0 | 40,000 | 0.00 |
| Project C | 1 | 80,000 | 2.50 |
| Company total | 3 | 200,000 | 3.00 |
The correct company TRIR is (3 × 200,000) ÷ 200,000 = 3.00. Averaging the three project rates gives (5.00 + 0.00 + 2.50) ÷ 3 = 2.50, which understates the real rate because Project B, with the fewest hours, counts as much as the two larger projects. The bigger the difference in hours between projects, the bigger the error.
Step-by-step roll-up
- 1. Fix the reporting period
Use the same period for cases and hours: a calendar year, a fiscal year, or a rolling 12 months. Mixing periods is the second most common error.
- 2. Collect hours per project from timekeeping
Use all employee hours worked, including overtime, and exclude paid time off. Pull them from payroll or time records, not estimates.
- 3. Assign every recordable case to one project
Each case on your OSHA 300 log should carry the project or site where the injury happened, so cases and hours line up.
- 4. Add cases and add hours separately
Sum cases across projects. Sum hours across projects. Do not add or average the individual rates.
- 5. Apply the formula once
Multiply total cases by 200,000, then divide by total hours. Repeat the same method for DART using DART cases.
- 6. Report the project rates beside the total
The company number answers “how are we doing”; the project rows answer “where should we look.”
You can check your math with the free TRIR and DART calculator, then compare the result with an industry benchmark using the TRIR industry average calculator.
Build a trend that is not noise
A contractor with 200,000 hours a year has very few recordable cases, so one additional case changes TRIR dramatically. To avoid overreacting:
- One practical option is a rolling 12-month TRIR as the headline so one bad month does not dominate the year (a Rivkor management suggestion, not an OSHA requirement).
- Show the case count and hours next to every rate so readers see the denominator.
- Add DART or days-away cases to show severity, not just frequency.
- Compare the company rate with a published benchmark for your industry, not with a number from another sector.
- Review monthly and at the end of each project, not only at year end.
Add leading indicators to the roll-up
TRIR is a lagging indicator: it only moves after someone is hurt. For multi-project companies, pair it with measures that move earlier and are less volatile:
- Near-miss and hazard reports per 10,000 hours, by project
- Percentage of scheduled inspections completed on time
- Corrective actions closed within the due date, and average days to close
- Share of workers with current required training
- Toolbox talks held versus planned
A project with a clean TRIR but few reported near misses may simply not be reporting. A project with a high near-miss count and a low TRIR may have a healthy reporting culture. Reading the two together gives a more honest picture.
Handling subcontractors and temporary workers
OSHA recordkeeping assigns the log to the employer that supervises the worker day to day, which can include temporary workers placed with you. Owners and general contractors, however, often want to see subcontractor safety performance as well. Keep two clearly labeled views: your own OSHA-log TRIR, and a separate view of subcontractor-reported rates collected for prequalification. Do not blend them into one number. When unsure which log an injury belongs on, check current OSHA guidance.
Why spreadsheets break at this step
A roll-up depends on three data sets staying aligned: incidents tagged to projects, hours by project, and the recordability decision for each case. In spreadsheets those usually live in different files owned by different people, and the roll-up becomes a manual project at every month end. Rivkor keeps incident records, OSHA logs, and rate calculations connected, and its multi-site rollups let managers see company-wide and per-site results with role-based access. See how the OSHA recordkeeping workflow produces the logs behind the rates, or read our guide to choosing EHS software for a small business if you are still comparing options. If you work in the trades, the construction EHS software page shows how this plays out on jobsites.
Frequently asked questions
Can I average the TRIR of each project?
No. Averaging project rates gives every project equal weight regardless of size. Add up the recordable cases and the hours across all projects, then apply the formula once: total cases × 200,000 ÷ total hours.
How often should I roll up TRIR?
One practical option is monthly review with a rolling 12-month view. Annual-only reporting can hide problems until it is too late to act. This is a management suggestion, not an OSHA requirement.
What should I track besides TRIR?
Leading indicators such as near-miss reports, inspection completion, corrective-action closure time, and training currency. They move before injuries do and give small contractors a more stable signal than a rate based on very few cases.
Do subcontractor hours count?
It depends on whose log the injury goes on. OSHA recordkeeping follows the employer who supervises the work day to day. Many general contractors also track subcontractor rates separately for prequalification, so keep the two views distinct.