Lost Time Injury Severity Rate (LTISR) Calculator

What is Lost time Injury Severity Rate?

A question 'How serious are the injuries? is replied by the severity rate which is defined as the number of days of lost time per 1000000 per million man-hours worked.

S = Mandays lost due to lost time injury x 1000000 / Manhours worked.

Since severity rate SR is based on the lost time injuries reportable to the statutory authorities, it should be used for official purposes only. In all other cases severity rate SL should be used for comparison purposes.

Here man-days lost due to temporary total disability and man-days lost according to schedule of charges for death and permanent disabilities are as given in Appendix A (15:3786-1983). In case of multiple injury, the sum of schedule charges shall not be taken to exceed 6000 man-days. In Appendix A, equivalent man-days for death and other total disablement are 6000, and they are gradually decreased with decrease in percentage of loss of earning capacity against named partial disablement.

Lost time Injury Severity Rate Calculator

Mandays lost due to lost time injury



Number of Manhours worked






Severity Rate

Calculate LTI Severity Rate Here