Skip to content
ENExplore Calculators

Incident Frequency Rate Calculator

Work out incident frequency rate instantly with clear inputs, formula shown and shareable results.

About Incident Frequency Rate Calculator

Incident frequency rate normalises incident count by exposure hours so organisations of different size can be compared. The base hours convention differs by region: 200,000 hours corresponds to 100 full time workers for a year and is the North American standard, while a million hours is common elsewhere.

Formulas

Frequency rate

Rate = incidents x base hours / hours worked

Common bases

200,000 hours equals 100 full time equivalents for a year; 1,000,000 hours is the international convention

Worked example

With the default values below, Incident Frequency Rate Calculator returns Incident frequency rate of 2.400. Change any input above and every figure here is recalculated in your browser.

Inputs used

Recordable incidentsminimum 0
6
Hours workedminimum 1 h
500,000 h
Base hours for the rateminimum 1 h
200,000 h

Results

Incident frequency rate
2.400
Incidents per million hours
12.000
Hours worked per incident
83,333 h
Rate per 100 full time workers
2.400

Step by step

  1. 1Values used
  2. 2Frequency rate
  3. 3Common bases
  4. 4Incident frequency rate= 2.400
  5. 5Incidents per million hours= 12.000
  6. 6Hours worked per incident= 83,333 h
  7. 7Rate per 100 full time workers= 2.400

Assumptions and limits

  • The result is derived only from the 3 inputs listed above. Anything not among them is not part of the calculation.
  • In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
  • Figures are rounded for display to 3 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

How is the Incident Frequency Rate figure worked out?

Rate = incidents x base hours / hours worked. Incident frequency rate normalises incident count by exposure hours so organisations of different size can be compared.

Why is the rate a poor sole measure of safety?

It is a lagging indicator dominated by low-consequence events and highly sensitive to reporting culture. A falling rate can reflect suppressed reporting rather than improved safety.

What values do I need to enter?

This calculator takes 3 inputs: Recordable incidents, Hours worked, Base hours for the rate. The pre-filled defaults are a realistic worked example — replace them with your own site or project figures.

Related Calculators

Incident Frequency Rate Calculator | Calcrivo