Lost Time Injury Rate

The lost time injury rate measures how many work injuries and illnesses cause an employee to miss at least one day of work, compared with the hours worked. It focuses on the more serious cases that take people off the job.

In OSHA terms, this is the days-away-from-work rate. BLS explains that it uses only the cases with days away from work in the standard incidence rate formula.

How Do You Calculate the Lost Time Injury Rate?

Count the cases on your OSHA 300 Log that involved days away from work. Multiply by 200,000, then divide by the total hours all employees worked.

Example: 2 days-away cases and 400,000 hours worked give (2 times 200,000) divided by 400,000, which equals 1.0 lost time cases per 100 full-time workers.

Some employers and countries use 1,000,000 hours as the base instead. Confirm the base before comparing your rate with anyone else's.

What Counts as a Lost Time Case?

A lost time case is a recordable injury or illness where the employee misses at least one full day of work after the day it happened. OSHA's rules count calendar days and cap the count at 180 days.

Cases with restricted work or job transfer but no missed days are not lost time cases. They fall into the broader DART rate instead.

Count each case once, in the year it was recorded, using the same method every year.

How Is Lost Time Injury Rate Different From TRIR?

TRIR counts every recordable case, including treatment beyond first aid with no missed work. The lost time rate counts only cases where the employee missed days.

That makes the lost time rate a better signal of severity. Two sites can have the same TRIR while one has far more cases that take people off the job.

Use them together. TRIR shows how often injuries happen, and the lost time rate shows how many of them are serious enough to cost days.

Why Does the Lost Time Injury Rate Matter to HR?

Lost time drives cost. Missed days mean wage replacement under workers' compensation, overtime or temporary labor to cover the work, and slower recovery for the team.

It also shows where return-to-work efforts could help. A site with many lost time cases may benefit from earlier contact and temporary duties for injured employees.

A manufacturing safety compliance article notes the cost risk of lost-time injuries for new hires, which is why training and onboarding matter.

How Should You Use the Rate?

• Track it with TRIR and the DART rate for a fuller picture.
• Review it by site, shift, job, and length of service.
• Look for patterns, such as new hires or one machine.
• Check that injuries are reported quickly and accurately.
• Set improvement goals as trends, not single-number targets.

A very low number can reflect good safety or weak reporting. Ask people whether they feel safe reporting injuries.

What Are the Limits of This Metric?

Small workforces see big swings. A single case in a 30-person company moves the rate sharply, so look at multi-year trends.

The metric ignores near misses and minor injuries, which are early warnings. It also depends on hours-worked data being right.

Treat it as one signal among several rather than a score of how safe the workplace is.

How Can Employers Lower Lost Time Cases?

Prevention comes first, but response matters too. Quick medical care, early contact, and temporary duties can shorten the time someone is away.

Look closely at the first months of employment, when training gaps cause many injuries. Strong onboarding, supervision, and clear job instructions reduce early lost time cases.

How Does HR Cloud Fit Into the Lost Time Injury Rate?

HR Cloud does not calculate injury rates. Its frontline HR software page lists safety compliance tracking for production and warehouse teams, but it does not describe injury rate reporting.

Pull the days-away cases from your OSHA 300 Log and hours from payroll, and calculate the rate in a spreadsheet.

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Frequently Asked Questions

Q: What is the lost time injury rate?

A: It is the number of injuries and illnesses causing days away from work per 100 full-time workers.

Q: What is the formula?

A: Days-away cases times 200,000, divided by total hours worked by all employees.

Q: Is lost time injury rate the same as TRIR?

A: No. TRIR counts all recordable cases, while the lost time rate counts only cases with days away from work.

Q: What is a lost time injury?

A: A work injury or illness after which the employee misses at least one full day of work after the day it happened.

Q: What is the difference between lost time rate and DART?

A: DART adds cases with restricted work or job transfer to the days-away cases.

Q: Why do some companies use 1,000,000 hours?

A: Some countries and companies use a larger base for frequency rates, so confirm the base before comparing.