TRIFR

• TRIFR counts more than lost time injuries. Most Australian construction companies include these categories.

• Fatality. A work-related death.

• Lost time injury (LTI). An injury that stops the worker from working at least one full shift after the day of the injury.

• Restricted work injury (RWI). The worker comes back to work on the next shift but cannot do their normal duties, so they are on suitable or alternative duties.

• Medical treatment injury (MTI). The injury needs treatment by a doctor or other medical professional beyond first aid, such as stitches or prescription medication.

First aid injuries are normally not included. Definitions are not set by law, so check the definitions in your company's reporting standard or the client contract, because they can change the result.

For a deeper look, read TRIFR and LTIFR Explained: The Two Safety Numbers Clients Ask For. Try the free LTIFR and TRIFR Calculator.

The TRIFR calculation is:

TRIFR = (number of recordable injuries x 1,000,000) / total hours worked

Use the same period for both numbers, often a rolling 12 months. Hours worked should include all workers covered by the reporting scope, which on most projects means subcontractor hours as well as direct employees.

Worked example. A project records 2 lost time injuries, 1 restricted work injury and 4 medical treatment injuries over 12 months, so 7 recordable injuries. Total hours worked over the same period are 560,000.

TRIFR = (7 x 1,000,000) / 560,000 = 12.5

That means 12.5 recordable injuries for every million hours worked on that project. If the same project had worked 1,120,000 hours with the same injuries, the TRIFR would halve to 6.25, which is why the hours figure matters as much as the injury count.

LTIFR (lost time injury frequency rate) only counts injuries that cost at least one full shift. TRIFR counts those plus restricted work and medical treatment injuries, so it is always equal to or higher than LTIFR for the same period.

Many builders and clients now prefer TRIFR because LTIFR can be kept artificially low by bringing injured workers back on alternative duties. TRIFR still captures those injuries. Neither measure says anything about near misses or the quality of risk controls, so most companies report them alongside leading indicators such as inspections, observations and toolbox talks.

• Mixing multipliers. Australia generally uses 1,000,000 hours. US-style TRIR uses 200,000 hours, so the numbers are not directly comparable.

• Leaving out subcontractor hours or injuries. Counting one without the other distorts the rate.

• Inconsistent classification. An injury reclassified from MTI to first aid can change the result. Apply the definitions the same way every time.

• Reading small numbers too closely. On a small project, one injury moves the rate a lot. Use rolling 12 months or company-wide figures for trends.