Incident rates · Lost-time cases · 1,000,000 h
Calculate LTIFR with consistent lost-time case definitions
Calculate lost-time injury frequency rate from lost-time injury cases and actual employee hours.
By HSECalc · Published
Check that this method fits your task
One-million-hour LTIFR arithmetic. Establish LTI inclusion rules using your reporting scheme; this page does not decide recordability or replace a country-specific return.
Choose your inputs and work through the steps
- Document the lost-time injury definition required by your reporting scheme. Set the workforce, period and treatment of contractor hours before counting cases.
- Count qualifying injury cases. Do not enter lost days, all incidents or all recordable cases unless those match the scheme’s actual definition.
- Enter matching actual hours worked. This calculator reports the result per one million hours; label that basis whenever you share it.
LTIFR = lost-time injury cases × 1,000,000 ÷ actual hours worked.
A worked example
Illustrative values explain the tool; they are not prescribed inputs for your work.
- 2 qualifying lost-time injury cases × 1,000,000 = 2,000,000.
- 2,000,000 ÷ 500,000 actual hours = 4.00.
- Report 4.00 LTIs per million hours, together with the period and scope.
Read the result and decide what needs checking
A change of reporting definition can create a change in the rate even when work conditions are unchanged. Explain breaks in a trend rather than presenting unlike periods as a continuous series.
Use case review and prevention indicators alongside the rate. It measures frequency of the specified cases, not the amount of lost time or every aspect of safety.
Common questions
Is LTIFR the same as TRIR?
No. The case definitions and normalising bases differ. Do not compare the values as equivalent scores.
What counts as a lost-time injury?
Apply the definition required by your reporting scheme consistently and document it.
Is a low LTIFR proof of good controls?
No. Review cases, exposure to hazards and other performance measures as well.
References and scope notes
Use the current official guidance and the instructions for your actual equipment. HSECalc is independent; a reference is not an endorsement. Read how we use methods and sources or report a correction.