What does “LTIR (lost-time injury rate)” mean?
Short answer
LTIR (lost-time injury rate) counts injuries that cost workdays per set block of hours. OSHA does not use the term, so confirm the formula before you compare.
Also known as: LTIR, lost time injury rate, lost-time case rate
The formula and its limits
OSHA publishes no rate named LTIR. Its rule counts cases with days away from work. OSHA and BLS figure rates as cases × 200,000 ÷ hours worked. So a U.S.-style LTIR is days-away cases × 200,000 ÷ hours.
That base is a habit, not a law. Customers, insurers, parent companies and other countries may define lost time and the hours base differently. Label every figure, for example 'LTIR per 200,000 hours'.
Example: 2 lost-time cases and 400,000 hours. 2 × 200,000 = 400,000. Divide by 400,000 to get 1.0.
What changes the number
- Days: OSHA counts calendar days (weekends too) from the day after the injury. Cap: 180.
- Restricted duty: DART includes it. Lost-time rates usually do not.
- Hours base: to restate a rate on B hours as per 200,000, multiply by 200,000 ÷ B.
- A rate per 1,000,000 hours becomes per 200,000 when you multiply by 0.2.
Mix-up: LTIR, TRIR and DART answer different questions. TRIR counts all recordable cases. DART counts days away plus restricted and transferred cases. LTIR is narrower: only cases where the employee was away from work.
Frequently asked questions
Is LTIR an OSHA metric?
No. OSHA's rates are the total case rate and the DART rate, both on 200,000 hours. LTIR is an industry label, so check how each customer or contract defines it.
How do I convert an LTIR to a per-200,000-hour rate?
Multiply it by 200,000 divided by the hours base it used. For a rate per 1,000,000 hours, multiply by 0.2. Only convert if both count the same cases.
Does LTIR include restricted duty cases?
Usually not. Lost time means the employee was away from work. Restricted work and job transfer count in OSHA's DART rate instead. Say which cases your LTIR includes.
Sources
- OSHA 29 CFR 1904.7: General recording criteria
- OSHA: Establishment-specific injury and illness data (rate definitions)
- BLS Handbook of Methods: Survey of Occupational Injuries and Illnesses, calculation
Reviewed against the sources above on Oct 5, 2026. Rules change: confirm current requirements with the issuing body or your counsel before relying on any summary.
Put the definition to work.
IncidentKit turns these terms into workflow: reports, investigations, corrective actions and packets.