TRIR vs LTIFR — how do you compare them?

The two formulas

TRIR = recordable cases × 200,000 ÷ hours worked. The 200,000 comes from 100 full-time employees working 40 hours a week for 50 weeks, so a TRIR of 2.2 means roughly 2.2 recordable cases per 100 workers per year.

LTIFR = lost-time injuries × 1,000,000 ÷ hours worked. Same shape, different base — and a narrower numerator, because only injuries that cost time are counted, not every recordable.

So the two differ on both axes at once: the denominator and the definition. That is what makes naive comparison so reliably wrong.

Recent US construction TRIR sits around 2.2

That is the benchmark your own number gets read against, and it is worth knowing before a client reads it for you.

But a benchmark is only useful if you are measuring the same thing. Before concluding anything from a comparison — between regions, between subcontractors, between years — check that both numbers use the same base and the same case definition.

And neither one tells you about fatalities

Both metrics count frequency, and frequency is dominated by minor events. A falling TRIR is a statement about cut fingers and sprains.

Serious injuries and fatalities have their own precursors — high energy, failed control — and they have to be tracked separately. Which is why sophisticated clients now ask for TRIR, DART and SIF-potential rates together, rather than accepting any one of them alone.

Terms

• LTI (Lost Time Injury)
• LTIFR (Lost Time Injury Frequency Rate)
• TRIR (Total Recordable Incident Rate)