What it means
LTIR counts the incidents where a worker lost time from work because of an injury or illness, and scales that count to hours worked.
The formula: LTIR = (number of lost time incidents x 200,000) / total hours worked by all employees in the same period.
Definitions vary. Some companies and countries use a different base, such as 1,000,000 hours, and some define a lost time case differently. State the base and the definition you used. This page uses the 200,000 hour base OSHA uses for its rates.
Why it matters
A case where someone couldn't work is hard to argue with. LTIR is a simple number for that. Owners and customers often ask for it, so be ready to say how you count it.
What it looks like on a site
- The lead counts only cases with time away from work, not restricted duty or medical treatment alone.
- Hours come from payroll and from your subcontractor records, the same source as TRIR.
- The report says which base was used, so a customer using a different one isn't misled.
- Prequalification forms get the number as you calculated it, with the definition written next to it.
This is general information, not legal advice. Check the current rule and your own procedures. Back to the glossary