Work out lost time injury rate instantly with clear inputs, formula shown and shareable results.
Lost time injury frequency rate counts only injuries causing at least one full shift away from work, normalised to a base of exposure hours, usually a million. Restricting the count to lost time injuries makes the measure less sensitive to first aid reporting practice but also much noisier for small organisations.
Lost time injury frequency rate
LTIFR = lost time injuries x base hours / hours worked
LTIFR = lost time injuries x base hours / hours worked. Lost time injury frequency rate counts only injuries causing at least one full shift away from work, normalised to a base of exposure hours, usually a million.
With few injuries, a single event moves the rate dramatically. A site working 100,000 hours a year sees its rate jump by ten points per injury on a million hour base.
This calculator takes 3 inputs: Lost time injuries, Hours worked, Base hours for the rate. The pre-filled defaults are a realistic worked example — replace them with your own site or project figures.