# What is our TRIR incident rate?

Works out OSHA’s total recordable incident rate (TRIR) and the DART rate per 100 full-time workers from the recordable cases and the hours worked in a year.

- Page: https://www.acalculator.org/everyday-life/trir-calculator
- JSON spec: https://www.acalculator.org/everyday-life/trir-calculator.json
- Version: 840ad37ab268

## Default answer

Example with the default inputs (Recordable cases 3, I know Hours worked, Hours worked 150,000): 3 recordable cases in 150,000 hours worked is a TRIR of 4.

## Inputs

| Key | Label | Description |
| --- | --- | --- |
| cases | Recordable cases | Work-related injuries and illnesses recorded on OSHA Form 300 for the year. |
| dart | DART cases | Optional: the recordable cases with days away from work, restricted work or a job transfer. |
| by | I know | The total hours all employees worked, or the number of full-time employees. |
| hours | Hours worked | Total hours all employees actually worked in the year, from payroll. |
| emp | Full-time employees | The average number of full-time employees; each counts as 2,000 hours a year. |

## Outputs

| Key | Label | Description |
| --- | --- | --- |
| trir | TRIR | Recordable cases × 200,000 ÷ hours worked. |
| dartRate | DART rate | DART cases × 200,000 ÷ hours worked. |
| hoursUsed | Hours worked | The hours typed, or employees × 2,000. |
| meaning | In words | The TRIR as cases per 100 full-time workers a year. |

## Method

TRIR = recordable cases × 200,000 ÷ hours worked; DART rate = DART cases × 200,000 ÷ hours worked.

## Assumptions

- 200,000 hours is 100 full-time employees working 40 hours a week for 50 weeks.
- With a head count, each full-time employee counts as 2,000 hours a year; payroll hours are more accurate.
- Cases are those recorded on OSHA Form 300 under 29 CFR 1904.

## Worked examples

1. cases = 3, by = hours, hours = 150,000 gives trir = 4, hoursUsed = 150,000. Source: OSHA, Clarification on how the formula is used by OSHA to calculate incident rates (2016-08-23): (injuries and illnesses × 200,000) ÷ employee hours worked; 200,000 is 100 employees working 40 hours a week, 50 weeks a year, https://www.osha.gov/laws-regs/standardinterpretations/2016-08-23 (retrieved 2026-10-03).
2. cases = 5, dart = 2, by = employees, emp = 50 gives hoursUsed = 100,000, trir = 10, dartRate = 4. Source: OSHA, Clarification on how the formula is used by OSHA to calculate incident rates (2016-08-23): (injuries and illnesses × 200,000) ÷ employee hours worked; 200,000 is 100 employees working 40 hours a week, 50 weeks a year, https://www.osha.gov/laws-regs/standardinterpretations/2016-08-23 (retrieved 2026-10-03).
3. cases = 7, dart = 3, by = hours, hours = 412,345 gives trir = 3.395215, dartRate = 1.455092. Source: OSHA, Clarification on how the formula is used by OSHA to calculate incident rates (2016-08-23): (injuries and illnesses × 200,000) ÷ employee hours worked; 200,000 is 100 employees working 40 hours a week, 50 weeks a year, https://www.osha.gov/laws-regs/standardinterpretations/2016-08-23 (retrieved 2026-10-03).

## FAQ

### How do I calculate TRIR?

Multiply the number of recordable cases by 200,000 and divide by the total hours all employees worked. 3 cases in 150,000 hours is 3 × 200,000 ÷ 150,000 = 4.0.

### Why 200,000?

It is the hours 100 employees work in a year at 40 hours a week for 50 weeks. Scaling to 200,000 hours makes the rate a number of cases per 100 full-time workers, so firms of any size compare.

### What is a good TRIR?

Lower is better, and it depends on the industry. Compare your rate with the average for your industry in the Bureau of Labor Statistics injury and illness survey for the same year.

### What is the DART rate?

Days Away, Restricted or Transferred: the same formula, counting only the recordable cases that kept a worker away from work, limited their duties, or moved them to another job. It is never above the TRIR.

### What if I do not know the hours worked?

Use the number of full-time employees; each counts as 2,000 hours a year. Payroll hours are better, because they leave out vacation, sick leave and holidays, and count overtime and part-time work.

### What counts as a recordable case?

A work-related injury or illness that needs more than first aid, or causes days away, restricted work, a transfer, loss of consciousness, or a significant diagnosis, as set out in OSHA’s recordkeeping rule, 29 CFR 1904.

## Sources

- OSHA, Clarification on how the formula is used by OSHA to calculate incident rates, standard interpretation of 2016-08-23 ((number of injuries and illnesses × 200,000) ÷ employee hours worked = incidence rate; 200,000 is the hours of 100 employees working 40 hours a week, 50 weeks a year). https://www.osha.gov/laws-regs/standardinterpretations/2016-08-23 (retrieved 2026-10-03)