Injury Frequency Rate

on . Posted in Safety Engineering

Injury frequency rate, abbreviated as IFR, is used to measure the frequency of workplace injuries and illnesses within a specific period, typically expressed as the number of injuries per unit of time worked.  It's an important indicator for assessing the safety performance of a workplace and tracking trends over time.

  • Number of Recordable Injuries and Illnesses  -  The total number of work related injuries and illnesses that required medical treatment, resulted in lost workdays, or meet other specific criteria for recordability.
  • Total Hours Worked by Employees  -  The total number of hours worked by all employees during the specified time period.
  • The constant 200,000  -  Used to normalize the rate to the number of injuries that would occur if 100 employees worked full time for a year (200,000 hours).

The injury frequency rate provides a standardized measure that allows organizations to compare safety performance across different time periods, departments, or companies.   A lower IFR indicates a lower rate of injuries relative to the number of hours worked, which suggests better safety performance.  Conversely, a higher IFR indicates a higher frequency of injuries and may suggest that safety measures need to be improved.


Injury Frequency Rate formula

\( IFR =  TNLTI \; 200,000 \;/\; THW \) 
\( IFR \) = injury frequency rate
\( TNLTI \) = total number of lost time injuries
\( THW \) = total hours worked


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Tags: Safety