AFR Calculator (Accident Frequency Rate)
Formula Reference
AFR = (Number of Accidents × Base) ÷ Total Hours WorkedFAR (Fatal Accident Rate) = (Number of Fatalities × 100,000,000) ÷ Total Hours Worked
Quick conversion: AFR (per 1,000,000) ÷ 5 ≈ Equivalent OSHA TRIR (per 200,000), since 1,000,000 ÷ 200,000 = 5. This is only an approximation — AFR and TRIR often differ in exactly which cases count as "reportable," not just the base multiplier.
Base Convention by Framework
| AFR (ILO / HSE UK / IOGP) | 1,000,000 hours |
| OSHA TRIR / DART | 200,000 hours |
| FAR (Fatal Accident Rate) | 100,000,000 hours (fatalities are rare — a larger base avoids meaningless tiny decimals) |
Illustrative Industry AFR Ranges (General Reference Only)
Frequently-cited general ranges: Oil & Gas ~1–2, Manufacturing ~3–5, Construction ~4–6, with many organizations targeting AFR below 1.0 as a "world-class" goal. These vary enormously by source, region, and exact accident-scope definition — always benchmark against your specific sector's published data (e.g., IOGP Safety Data Report for oil & gas) rather than a generic number.Methodology, interpretation & sources
Purpose. AFR = Accident Frequency Rate. The international (ILO/HSE UK/IOGP) equivalent of OSHA's incident rate, standardized per 1,000,000 hours worked rather than 200,000 — widely used in UK, European, Middle Eastern, and multinational HSE reporting.
How to use the result. Start with source data you can verify, enter values on a consistent unit and time basis, and record the assumptions used. The main inputs on this page include Reporting Base, Number of Accidents Your organization's defined "reportable accident" scope — e.g., RIDDOR-reportable (UK), all recordables, or lost-time injuries. Be consistent period to period., Total Hours Worked, Number of Fatalities (optional) If provided, also calculates the Fatal Accident Rate (FAR) per 100,000,000 hours., Your Name, Email. Re-run the calculation when those assumptions change rather than carrying an old result forward.
Decision use. Use this calculator to standardize a safety-performance indicator from your own verified incident and exposure data. Consistent definitions are essential when comparing sites or time periods.
Limitations. Confirm that the numerator event definition and denominator exposure-hours basis match the reporting framework used by your organization or regulator.
Primary references. Use the current edition/version that applies to your jurisdiction and organization:
Editorial note. Prepared and maintained by Impact Tech Solutions. Editorially updated 28 September 2026. No individual professional credential is claimed on this page; high-consequence, statutory, tax, engineering or health decisions should be independently verified against the current primary source and, where required, a qualified professional.