Lost Time Injury Frequency Rate

By Safeopedia Staff
Last updated: February 23, 2024

What Does Lost Time Injury Frequency Rate Mean?

Lost time injury frequency rate (LTIFR) refers to the number of lost time injuries (workplace injuries that resulted in an employee being unable to work their next full workday) which occurred during a given period relative, relative to the total number of hours worked. In many countries, the figure is typically calculated per 200,000 or 1,000,000 hours worked.

LTIFR is considered a lagging indicator of safety, meaning that it measures past safety performance rather than being a predictor of future safety performance.

It is also of limited use to very small organizations, as the results are more meaningful when measured across a large group of workers.

Safeopedia Explains Lost Time Injury Frequency Rate

Companies that track their lost time injury frequency rates can use the results to gauge the effectiveness of their safety programs. While calculating your LTIFR once won’t provide a wealth of insights into an organization’s safety performance, but calculating them regularly can indicate whether the rate of injuries is improving or increasing over time.

Metrics such as LTIFR and LTIIR are used by regulatory bodies like the Occupational Health and Safety Administration (OSHA). The LTIFR can be used to compare the frequency rate of occurrence of different types of injuries.

How to Calculate LTIFR

LTIFR is calculated using two pieces of essential information:

  • The number of lost time injuries within a given time frame
  • The number of hours worked in that same time frame

The other element of the equation is a standardized rate, representing the number of hours worked. This is typically 200,000, which is roughly equivalent to 100 employees each working 2,000 hours (about 40 hours per week over the course of a year). However, some companies will use 1,000,000 as the standardized rate. In either case, the standardized rate is used to avoid getting a LTIFR that is a small number or decimal, making it more difficult to communicate or compare the rate of injuries.

The formula for calculating LTIFR is:

LTIFR = (LTIs x Standardized Rate) / (Hours Worked)

For example, let’s suppose there were 5 lost time injuries over the last year. During that same time frame, the employees worked a total of 1,584,391 hours. Using a standardized rate of 1,000,000, the LTIFR would be:

5 x 1,000,000 = 5,000,000

5,000,000 / 1,584,391 = 3.15

This LTIFR of 3.15 means that there were 3.15 lost time injuries for every 1,000,000 hours worked during the year.

Ready to learn more? Check out our free whitepaper: Are You Behind the Safety Curve?

Sign up to the Safeopedia Newsletter to get more great safety info delivered right to your inbox!



Lost Time Case Rate (LTCR)

Lost Time Incident Rate (LTIR)

Lost Time Accident Rate (LTAR)

Share This Term

  • Facebook
  • LinkedIn
  • X

Related Reading

Trending Articles

Go back to top