Safety · Workplace injury rates

TRIR and DART calculator.

Enter your recordable cases, your DART cases and the hours your employees worked in the year.

The Bureau of Labor Statistics example company logged 7 cases over 400,000 hours worked: (7 x 200,000) / 400,000 = a TRIR of 3.5. Its 3 most serious cases give (3 x 200,000) / 400,000 = 1.5.

Verified October 26, 2026Runs in your browser

Your numbers

Your result

What TRIR and DART measure

TRIR puts injuries on a common footing. Ten injuries in a 15-person shop and ten in a 1,500-person plant are very different stories, so the rate divides the count by hours worked and scales it to the hours of 100 full-time workers. DART narrows the count to the more serious cases: those with days away from work, job restriction or transfer. Both come out as cases per 100 full-time workers per year, which is why they are quoted as small numbers like 3.5 rather than as percentages.

This page does the arithmetic and shows the inputs next to the answer so it can be checked.

Worked example

The BLS example company, ABC Company, had 7 injuries and illnesses logged and 400,000 hours worked by all employees. TRIR = (7 x 200,000) / 400,000 = 3.5. For its 3 most serious cases, (3 x 200,000) / 400,000 = 1.5; this page treats those as the DART cases. As a check on scale, 400,000 hours is about 200 full-time workers at 2,000 hours a year.

How it is calculated

Rate = (number of cases x 200,000) / total hours worked by all employees. BLS gives this as “(Number of injuries and illnesses X 200,000) / Employee hours worked = Incidence rate”.
The 200,000 is the hours of 100 employees working 40 hours a week for 50 weeks a year, which BLS calls the standard base for incidence rates.
TRIR uses all recordable cases. DART uses only cases with days away from work, job transfer or restriction, or both.
Hours worked should not include time not worked even if paid, such as vacation, sick leave or holidays, per BLS.

Basis and example as published on the BLS page opened October 26, 2026. This page does not decide whether a given case is recordable; that is an OSHA recordkeeping determination you make from your own log.

What this does not cover

Whether a case is recordable, or which cases count as days away, restricted or transferred. Use your OSHA 300 log.
Industry comparison. This page shows no benchmark rate; look up your NAICS code in the BLS tables for that.
Fatalities, near misses and first-aid-only cases, which are outside a recordable count.

Sources

U.S. Bureau of Labor Statistics: How to compute your firm’s incidence rate for safety management (formula, 200,000-hour base, ABC Company example) (opened 2026-10-26)

Common mix-ups

Often assumedThe 200,000 in the formula is a number of employees.

What the source saysBLS says the 200,000 hours represents the equivalent of 100 employees working 40 hours per week, 50 weeks per year, and provides the standard base for the incidence rates. It is an hours base, not a headcount. ^[1]
Often assumedPaid vacation, sick leave and holidays count as hours worked.

What the source saysBLS says hours worked should not include any nonwork time, even though paid, such as vacation, sick leave, holidays, etc. ^[1]

BLS: How to compute your firm's incidence rate for safety management

Checked against these sources on 2026-10-26.

Frequently asked questions

What is the TRIR formula?

BLS gives (number of injuries and illnesses x 200,000) / employee hours worked. The 200,000 is the yearly hours of 100 employees working 40 hours a week for 50 weeks.

What does DART stand for?

Days away, restricted or transferred. BLS describes DART as injury and illness cases with days away from work, or job transfer or restriction, or both.

Why 200,000 hours?

BLS says it represents the equivalent of 100 employees working 40 hours per week, 50 weeks per year, and provides the standard base for the rates.

Which hours go in the denominator?

Hours actually worked by all employees. BLS says hours worked should not include non-work time, even if paid, such as vacation, sick leave or holidays.

Is a TRIR of 3.5 good?

This page does not say. A rate only means something against the same kind of operation, so compare against your own industry’s published BLS rate for the same year.

Estimate only

This page is a planning aid, not safety, engineering or legal advice. Results use the numbers you enter and the formulas and sources named above, as read on October 26, 2026. Everything runs in your browser; nothing is sent anywhere.