The Definition of Lost Time Injury Frequency Rate (LTIFR)

Definition of Lost Time Injury Frequency Rate (LTIFR)

Lost time injury frequency rate (LTIFR) is the number of lost time injuries that occur in a workplace per one million hours worked. Normalizing by hours worked lets organizations compare safety performance over time and between sites, contractors and companies of different sizes.

LTIFR is widely used in Australia, New Zealand, the UK and in global industries such as mining, oil and gas, construction and utilities. Safe Work Australia and many industry bodies publish LTIFR benchmarks. In the United States, the closest equivalents are OSHA-based rates such as the DART rate, which use 200,000 hours (100 full-time workers for one year) instead of one million.

Like other injury rates, LTIFR is a lagging indicator. It shows past results, not the current level of risk.

How to Calculate LTIFR

Formula

LTIFR = (Number of lost time injuries in the period × 1,000,000) ÷ Total hours worked in the period

Example calculation

A company records 4 lost time injuries in a year. Its employees and included contractors worked a total of 850,000 hours.

LTIFR = (4 × 1,000,000) ÷ 850,000 = 4.7

This means the company had about 4.7 lost time injuries for every million hours worked.

Getting accurate data

• Use actual hours worked, including overtime, rather than estimates where possible.
• Decide whether contractors are included and apply the rule consistently.
• Use a clear, written definition of a lost time injury.
• Report rolling 12-month figures to reduce the effect of month-to-month swings.

Using LTIFR Well

Strengths

• Simple to calculate and widely understood.
• Allows fair comparison between sites with different workforce sizes.
• Often required by clients, regulators and in tender submissions.

Limitations

• It does not reflect how serious injuries are. A sprain and an amputation each count as one LTI. Pair it with a severity rate.
• Small sites with few hours worked can see large swings from a single injury.
• It can be manipulated by underreporting or by using restricted duties to avoid lost days.
• A low LTIFR does not mean serious risks are under control. Many fatal incidents happen at sites with good LTIFR records.

For a fuller picture, use LTIFR in a balanced set of key performance indicators (KPIs) that also includes leading indicators and measures of serious incident potential.

Example of LTIFR

A mining contractor operated three sites. Site A reported 2 LTIs over 400,000 hours, Site B reported 2 LTIs over 1.6 million hours, and Site C reported none over 300,000 hours. Looking only at injury counts, Sites A and B seemed the same.

Calculating LTIFR showed Site A at 5.0 and Site B at 1.25, so Site A's injury rate was four times higher. The safety team focused support on Site A. They also noted that Site C's zero result was based on relatively few hours and reviewed its near miss reporting, which turned out to be very low, to check that injuries were not being missed.

Frequently Asked Questions: LTIFR

What is a good LTIFR?

It depends on the industry. High-risk industries such as construction and mining usually have higher rates than offices. Compare your result with published benchmarks for your sector and with your own trend over time.

What is the difference between LTIFR and TRIR?

LTIFR counts only lost time injuries per million hours. TRIR counts all OSHA recordable injuries and illnesses per 200,000 hours, including cases without lost time.

Why use one million hours?

One million hours is a common international standard. It produces numbers that are easy to compare, though some organizations use 200,000 hours to match OSHA rates.