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Injury rate calculator: TRIF, TRIR, DART and lost time

Last updated: Written by Blake Cowan, NCSO

Three rates from four numbers, worked out in your browser, with the arithmetic shown so you can defend the figure you submit.

The short answer

TRIF equals your recordable injuries multiplied by 200,000, divided by total hours worked. The same formula gives you DART and your lost time rate, counting narrower sets of the same injuries. Canada tends to say TRIF and the United States says TRIR, and both use the 200,000 basis, so one calculation answers both.

Put your numbers in and it works all three out. Nothing is stored and nothing is sent anywhere, because the arithmetic happens in your browser.

Work out your rate

Every hour actually worked by everyone, for the period you are reporting. Leave out vacation, statutory holidays and sick time, because nobody was exposed to a hazard during those.

Anything beyond first aid. This is the number clients ask for most.

Enter hours worked first

The subset of recordables that changed what the worker could do.

Enter hours worked first

The subset where the worker missed time beyond the day of injury.

Enter hours worked first

The formula, so you can check it by hand

If the calculator will not run, or you would rather see it done, here it is in full.

Rate equals count times 200,000, divided by total hours worked.

Take a company with 250,000 hours worked in a year, which is roughly 125 people. Over that year they had 3 recordable injuries. One of those put somebody on light duties for a fortnight, and one of those cost a week off work.

Comparison table.
What you are working outThe arithmeticResult
TRIF or TRIR3 times 200,000, divided by 250,0002.40
DART rate2 times 200,000, divided by 250,0001.60
Lost time rate1 times 200,000, divided by 250,0000.80

Scroll the table sideways to see every column. The first column stays in place.

Notice the DART count includes the lost time case. A worker who missed a week was also away from their job, so they belong in both. Your DART can never exceed your TRIF, and your lost time rate can never exceed your DART. If they do, something has been counted in the wrong bucket, and that is worth finding before a client does.

Where the 200,000 comes from

It is 100 workers, at 40 hours a week, for 50 weeks. That is the whole story.

The point of it is comparison. A raw injury count tells a client nothing, because four injuries at a company of twelve and four at a company of six hundred are not the same event. Dividing by hours and multiplying by a fixed number puts every company on the same scale, so a rate of 2.4 means the same thing whoever reports it.

Getting the hours right matters more than the injuries

Most people concentrate on counting injuries correctly and then guess at hours. It is the wrong way round, because hours is the bigger number and a sloppy estimate moves the result further than a debatable injury does.

Include every hour actually worked, by everyone. Overtime. Supervisors. The office. Working owners.

Leave out vacation, statutory holidays, sick leave and any other paid time when nobody was near the work. Padding the denominator with paid time off makes your rate look better, and it is visible to anybody who compares your submission against your payroll records.

If you genuinely do not have hours, the accepted estimate is 2,000 hours per full time worker per year. Use it as a fallback and say that is what you did, rather than presenting an estimate as a measurement.

TRIF, TRIR, TRIFR, TCR, and why the acronym is the least of it

Same argument as the one about JSAs and JHAs: the vocabulary follows whoever trained the person asking, not a standard.

Canadians say TRIF. Americans say TRIR. You will also meet TRIFR, TCR and total recordable case rate. On the 200,000 basis these are the same calculation, and swapping the name does not change the number.

What genuinely changes the number is the definition of recordable, and that is worth a conversation rather than an assumption. What counts as a recordable injury is where most wrong rates actually come from, and it is almost always the same mistake in the same direction.

So is your number any good

That depends entirely on your industry and on who is asking, and anybody quoting you a single national target is guessing.

What TRIF clients actually require covers the thresholds ISN, Avetta and ComplyWorks clients set, and what happens when you sit above one. Canadian injury rate benchmarks has the published provincial numbers, along with the reason you cannot compare them to each other as directly as everybody does.

And if the number is worse than you would like, how to actually lower it is the practitioner answer, which has more to do with modified work and what you count than with posters.

Free templates

The incident and near miss form the recordable count comes from, if you do not already have one you trust.

Incident and near miss report

An investigation form that pushes past worker error to the causes an auditor will ask about.

Direct download. No email, no signup, no form.

Print ready PDF and editable DOCX, no email required, and the full library has the rest. If you would rather have the whole program written and mapped to your certifying partner's audit, that is the paid work, and the software that holds it is free either way.

Questions people actually ask

How do you calculate TRIF?
Multiply your recordable injuries by 200,000, then divide by the total hours everyone actually worked. The 200,000 is what 100 full time workers put in over a year, so the answer reads as injuries per 100 workers. A company with 3 recordables over 250,000 hours has a TRIF of 2.40.
Is TRIF the same as TRIR?
For practical purposes yes. TRIF is the Canadian habit and TRIR is the American one, and both use the same 200,000 hour basis, so a number calculated one way is valid for the other. You will also meet TRIFR, TCR and total recordable case rate. Ask which definition of recordable the client wants rather than which acronym, because that is the part that actually changes the answer.
What hours do I include in total hours worked?
Every hour actually worked by everyone on the payroll, including overtime, supervisors and office staff. Leave out vacation, statutory holidays, sick leave and any other paid time when nobody was exposed to a hazard. Including paid time off inflates your denominator and quietly makes your rate look better than it is, which an auditor can unpick from your payroll records.
Why is the multiplier 200,000 and not 1,000,000?
200,000 is 100 workers times 40 hours times 50 weeks, and it is the basis used by OSHA and by Canadian certifying partners and prequalification platforms. The 1,000,000 basis is real but belongs to the UK, Australia and New Zealand. Mixing them produces an answer five times out, which is the most common way these numbers get submitted wrong.
What is the difference between TRIF, DART and the lost time rate?
They are the same formula counting narrower sets of the same injuries. TRIF counts everything recordable. DART counts only the ones that led to days away, restricted duty or a job transfer. The lost time rate counts only the ones where somebody missed time. So your DART can never be higher than your TRIF, and if it is, something is miscounted.
Do I need to include subcontractors in my rate?
It depends on who is asking, and this catches people out. Some clients want your own employees only, some want everyone who worked under your supervision on their site. The hours and the injuries have to come from the same population or the rate is meaningless. Get the client's definition in writing before you submit, because resubmitting a corrected rate looks far worse than asking.

Next step

Take the templates and use them, whether or not you ever talk to us. If you would rather not build the program yourself, we will build it inside the app and keep it current.