Lost Time Incident Rate (LTIR) Calculator
Enter the total number of incidents resulting in time away from work during the period.
Enter the total number of hours worked by all employees during the same period.
Your Lost Time Incident Rate is:
0.00
How to Calculate Lost Time Incident Rate (LTIR)
The Lost Time Incident Rate (LTIR) is a lagging safety indicator that measures the number of lost time incidents per 100 full-time employees over a specific period (usually one year). It is a critical metric for Environmental, Health, and Safety (EHS) professionals to benchmark safety performance against industry standards.
The LTIR Formula
The standard formula used by OSHA (Occupational Safety and Health Administration) and most international safety organizations is:
LTIR = (Number of Lost Time Incidents x 200,000) / Total Hours Worked
Understanding the Variables
- Number of Lost Time Incidents: This refers to the count of work-related injuries or illnesses that resulted in the employee being unable to work on a subsequent workday. It does not include incidents where the employee could return to light duty or restricted work.
- Total Hours Worked: This is the sum of all actual hours worked by all employees during the reporting period. It includes overtime but excludes vacation, sick leave, and holidays.
- The 200,000 Constant: This number represents the hours worked by 100 full-time employees in one year (100 employees x 40 hours/week x 50 weeks/year). It standardizes the rate so companies of different sizes can be compared fairly.
Example Calculation
Let's say a manufacturing plant has the following data for the year:
- Incidents: There were 3 injuries resulting in lost time.
- Hours: The workforce logged a total of 450,000 hours.
Using the formula:
LTIR = (3 x 200,000) / 450,000
LTIR = 600,000 / 450,000
LTIR = 1.33
This means that for every 100 full-time employees at this plant, 1.33 lost time incidents occurred during the year.
Why LTIR Matters
Calculating your LTIR allows you to:
- Benchmark Performance: Compare your safety record against industry averages (BLS data).
- Identify Trends: Track whether your safety programs are effectively reducing severe injuries over time.
- Lower Costs: High LTIRs often correlate with higher insurance premiums and workers' compensation costs.
LTIR vs. TRIR
While LTIR focuses specifically on incidents resulting in days away from work, the Total Recordable Incident Rate (TRIR) includes all recordable incidents (medical treatment beyond first aid, restricted work, and lost time). Consequently, your TRIR will always be equal to or higher than your LTIR.