Tracking & calculating Lost Time Incident Rate (LTIR)

There’s no shortage of metrics to capture in your environmental, health and safety strategy. Figuring out which ones can make the biggest impact can seem daunting, but many of them are critical to your organization’s success. According to our partners at Sedgwick, when creating your EHS strategy, recording your Lost Time Incident Rate (LTIR) should be a priority.

What is lost time incident rate?

Lost time incident rate is a standard OSHA and PERRP metric that calculates the number of incidents that result in time away from work. Not all recordable incidents result in lost time, which is why there is a separate calculation for these more severe incidents.

For example, a workplace injury where an employee breaks his or her arm on the job and misses work the next day would be included in an LTIR report. A similar situation where an injured employee can work the next day would not be included in this metric.

How to calculate lost time incident rate

The formula to use: (Number of lost time cases x 200,000)/total number of hours worked by employees

The figure 200,000 is a standard number to measure incident rates so companies of varying sizes can be compared fairly. This figure was determined by multiplying 100 employees by 40 hours (a standard work week) by 50 weeks (assuming each employee takes two weeks of vacation). The resulting figure indicates the number of employees who lost time due to an incident.

For example, if you have 40 full-time employees and 3 incidents that resulted in lost time, your calculation will look like this: (3 x 200,000) / 80,000 (40 employees x 40 hours per week x 50 weeks per year)

Your lost time incident rate would be 7.5, which means that for every 100 employees, 7.5 have experienced lost time due to an incident.

The importance of tracking lost time incident rate

It might sound like just another metric, especially if you’re already obligated by OSHA/PERRP to record it. But even if no one is forcing your hand, this piece of data can prove beneficial to your company.

For starters, calculating your lost time incident rate lets you know how much impact those incidents have on your organization and if the trend is improving or worsening over time.

Your lost time incident rate may also affect your business insurance rates. An increase in this figure may trigger a series of other events, including a hike on your insurance premiums.

Another benefit is that this statistic is impossible to over-report, unlike recordable incidents. Some companies record incidents that shouldn’t be recorded for fear of becoming non-compliant with OSHA requirements. Reporting unnecessary incidents exaggerate your figures, since LTIR focuses only on incidents resulting in time away from work, there’s no way for you to skew the results so you get a more accurate idea of your safety status.

Making the most of lost time incident rate reporting

LTIR is a lagging indicator, meaning it uses data from incidents that have already happened. This figure on its own can’t help you forecast future incidents, but it can prove useful over time.

Many medium- and large-sized organizations calculate this rate monthly and track the trends from month to month. You can compare this rate to activities in your safety program to help gauge their effectiveness. For example, if you implement a new form of training at the beginning of the year and notice your LTIR decreases from the previous year, you might be inclined to believe your safety training had something to do with it.

If you notice your rate starts to climb, you’ll know to investigate it sooner than later. If they decline, you’ll know something in your safety program is working.


The Division of Safety & Hygiene’s safety, industrial hygiene and ergonomics specialists can help you develop effective strategies to make your workplace safer and healthier. They can visit your workplace or consult with you by telephone or email. These services are available for any private or public employer. BWC also offers specialized options for certain employers. You can request these services online at: or 1.800.644.6292

For more information, please contact Craig Lanken at 330.472.1656 or