Incident rates · Injury cases · 1,000,000 h
Calculate injury frequency rate on a million-hour basis
Calculate a frequency rate for new occupational injury cases using a fixed one-million-hour basis.
By HSECalc · Published
Check that this method fits your task
Use new injury cases under your defined recording scope. This broader numerator differs from LTIFR’s lost-time subset. This is not an accident-per-worker incidence rate.
Choose your inputs and work through the steps
- Define the population and the new occupational injury cases included in the report. Keep an event count separate from the number of injury cases it caused.
- Gather actual worked hours for that same population and period. Do not combine employee-only cases with a denominator that silently includes unrelated workforces.
- Multiply the case count by one million, divide by hours, and state the case definition next to the result.
Frequency rate = new occupational injury cases × 1,000,000 ÷ hours worked. Match the numerator and denominator populations.
A worked example
Illustrative values explain the tool; they are not prescribed inputs for your work.
- 6 new injury cases × 1,000,000 = 6,000,000.
- 6,000,000 ÷ 750,000 hours = 8.00.
- Keep the label “new injury cases per million hours” with the result.
Read the result and decide what needs checking
One accident may injure more than one person. If the reporting scheme counts injury cases, replacing them with accident events changes the measure.
This rate is not an injury-per-worker incidence rate. Comparing it to LTIFR also needs matching case definitions, not just the same hours base.
Common questions
Do I enter accidents or injured people?
Count injury cases under your recording rules. One event can produce more than one injury case; keep that distinction explicit.
Can I compare this with LTIFR?
Only after aligning case definitions. LTIFR normally restricts the numerator to lost-time cases.
Why not multiply by 100,000?
This version deliberately uses one million hours. Other schemes use other bases; label and compare like with like.
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.