Zerdly

TRIFR Calculator

TRIFR (Total Recordable Injury Frequency Rate) expresses how many recordable injuries occurred per a fixed block of hours worked, so sites of different sizes can be compared fairly.

100% FreeRuns in your browserBasic
How to use this calculator

Enter Values

Enter your values and press Calculate to see results.

How to use this calculator

  1. Enter the total number of recordable injuries for the period (fatalities, lost-time injuries, restricted-work and medical-treatment cases — whatever your scheme classes as recordable).
  2. Enter the total person-hours worked over the same period, across every worker included in the count.
  3. Leave the exposure base blank to use the standard 1,000,000 hours, or enter 200,000 if you report on OSHA's per-100-full-time-worker basis.

How it works

TRIFR (Total Recordable Injury Frequency Rate) expresses how many recordable injuries occurred per a fixed block of hours worked, so sites of different sizes can be compared fairly. The formula is TRIFR = (total recordable injuries × exposure base) ÷ total hours worked. The exposure base is 1,000,000 hours under the Australian/international convention; OSHA's equivalent (TRIR/TCIR) uses 200,000 hours, which represents 100 full-time workers over a year.

The calculator multiplies your recordable count by the chosen base and divides by the hours worked, then reports the rate to two decimals along with a plain-language band. The band is an illustrative reference only — real benchmarks vary widely by industry and jurisdiction. Because TRIFR counts only recordable events, both the injury classification and the hours total must be measured consistently for the rate to be meaningful or comparable over time.

Worked example

5 recordable injuries over 1.2 million hours. A site records 5 total recordable injuries across 1,200,000 person-hours worked in the year. Using the standard 1,000,000-hour base: TRIFR = 5 × 1,000,000 ÷ 1,200,000 = 4.17. The result shows a TRIFR of 4.17 per million hours, flagged as low relative to many heavy-industry benchmarks.

Common mistakes

  • Using hours for one team but injuries for the whole site (or vice versa) — the recordable count and the hours worked must cover exactly the same people and period.
  • Mixing exposure bases: a TRIFR on a 1,000,000-hour base is not comparable to a rate calculated on OSHA's 200,000-hour base without converting.
  • Counting only lost-time injuries — that gives LTIFR, not TRIFR. TRIFR includes medical-treatment and restricted-work cases as well.

Frequently asked questions

What is the difference between TRIFR and LTIFR?

LTIFR counts only lost-time injuries (those causing at least one full shift off work), while TRIFR counts all recordable injuries — lost-time, restricted-work and medical-treatment cases. TRIFR is therefore usually the higher and broader figure.

Why is the exposure base 1,000,000 hours?

One million hours is the common Australian and international convention, giving a rate that's easy to compare between sites. OSHA in the US uses 200,000 hours instead (100 workers × 2,000 hours a year). Enter whichever base your reporting scheme requires — the tool defaults to 1,000,000.

What counts as a recordable injury?

Definitions vary by jurisdiction and by company policy. Broadly it means any work-related injury or illness beyond simple first aid — fatalities, lost-time injuries, restricted-work cases and medical-treatment cases. Always confirm the exact classification against your WHS/OSH rules before reporting a TRIFR.

Related tools

Explore more in Safety, Workplace Risk & Compliance Helpers.

Tip: Enter any known values to calculate the remaining results.

All calculations run in your browser. Your inputs are never saved or transmitted.