LTIFR calculator
Lost-time injury frequency rate and total recordable injury frequency rate, per 1,000,000 hours worked as South African mining reports them. Three numbers from your incident register and your payroll hours.
Injuries where the person could not work their next scheduled shift.
Medical treatment and restricted work cases that were not lost-time injuries. Leave at 0 if you only need LTIFR.
From payroll or the clocking records, including contractors if your report includes them.
Basis
LTIFR = lost-time injuries × basis ÷ hours worked. TRIFR = (lost-time + other recordable injuries) × basis ÷ hours worked.
Why South African and US figures differ by five
1,000,000 hours
The basis used in South African mining reporting; the Minerals Council South Africa publishes the industry's fatality and injury rates per million hours worked. Use it for a Mine Health and Safety Act report, a management review or a tender.
200,000 hours
The US OSHA basis: 100 full-time workers at 40 hours a week for 50 weeks. A figure from a US parent company, a contractor's international reporting or an American textbook is on this basis and is five times smaller for the same injuries and hours.
Asked for a TRIR on a tender, or comparing with a US figure? TRIR vs LTIFR: both formulas, a worked example and how to convert.
LTIFR, explained
How do you calculate LTIFR?
LTIFR is the number of lost-time injuries in the period, multiplied by 1,000,000, divided by the hours worked in the same period. A site with 2 lost-time injuries and 400,000 hours worked has an LTIFR of 5.00. Use the same hours basis every month and state whether contractors are included.
What counts as a lost-time injury?
A work-related injury that leaves the person unable to work their next scheduled shift, counted from the day after the injury. A case treated and returned to full duty the same shift is a medical treatment case, not a lost-time injury. Your reporting standard decides how fatalities and restricted work are counted; record the rule and apply it the same way every period.
What is the difference between LTIFR and TRIFR?
LTIFR counts only lost-time injuries. TRIFR, the total recordable injury frequency rate, counts lost-time injuries plus medical treatment and restricted work cases, so it is always equal to or higher than LTIFR. Both are per 1,000,000 hours in South African reporting and per 200,000 hours in US OSHA material.
The rate is only as good as the incident register behind it
Inspecable does not calculate LTIFR; it keeps the record you calculate it from. Incidents, near misses and observations are reported on an Android phone with no signal, each one gets a root cause and a corrective action that cannot close without evidence, and the month's counts come from the records rather than from memory.