Accident Frequency Rate (AFR) Calculator
Calculate your workplace safety performance based on UK standards.
Total RIDDOR reportable injuries or lost-time incidents in the period.
Total hours worked by all employees during the period.
Please enter a valid number of hours greater than 0.
Select the standard multiplier for your industry reporting.
Per 100,000 Hours (Standard UK/HSE Benchmark)
Per 1,000,000 Hours (Common in Oil & Gas / International)
Per 200,000 Hours (OSHA / US Standard)
Accident Frequency Rate (AFR):
0.00
accidents per 100,000 hours worked
How to Calculate Accident Frequency Rate in the UK
The Accident Frequency Rate (AFR) is a critical Key Performance Indicator (KPI) used by Health and Safety professionals across the United Kingdom to measure the effectiveness of safety protocols. Unlike a simple count of accidents, the AFR normalizes the data against the number of hours worked, allowing for fair comparisons between small companies and large corporations.
The AFR Formula
The standard formula used to calculate the Accident Frequency Rate is:
AFR = (Total Number of Accidents / Total Number of Man-Hours Worked) × Factor
In the UK, the Factor is typically 100,000. This represents the rate of accidents per 100,000 hours worked (roughly equivalent to 50 people working a 40-hour week for a year). However, some industries, particularly those with international operations or high-risk sectors like Oil & Gas, may use 1,000,000 as the multiplier.
Definitions of Inputs
- Number of Reportable Accidents: Under UK RIDDOR (Reporting of Injuries, Diseases and Dangerous Occurrences Regulations), this typically includes specified injuries, accidents resulting in over-7-day incapacitation, or major injuries. Some companies calculate AFR based solely on "Lost Time Injuries" (LTI).
- Total Man-Hours Worked: The sum of all hours worked by all employees (and relevant contractors) within the specific time period (e.g., monthly, quarterly, or annually).
Example Calculation
Imagine a construction firm in London has the following data for the year:
| Metric | Value |
|---|---|
| Total Accidents (LTIs) | 4 |
| Employees | 150 |
| Hours worked per year | 300,000 |
| Calculation Factor | 100,000 |
Calculation: (4 ÷ 300,000) × 100,000 = 1.33
This means the company experienced 1.33 accidents for every 100,000 hours of work performed.
Why is AFR Important?
Tracking your AFR allows you to:
- Benchmark Performance: Compare your safety record against industry averages published by the HSE (Health and Safety Executive).
- Identify Trends: A rising AFR indicates deteriorating safety conditions, even if the total number of accidents seems low due to fewer hours worked.
- Tender Requirements: Many UK construction and public sector tenders require disclosure of AFR stats for the past 3-5 years.