UK HR Term
Bradford Factor
The Bradford Factor is a formula used to score employee absence by weighting frequent short spells more heavily than occasional long ones. The score is calculated as S² × D, where S is the number of separate absence spells and D is the total days absent.
In plain English
Developed at Bradford University Management Centre in the 1980s, the Bradford Factor is an absence-management tool that gives a single numeric score reflecting the disruption caused by an employee's pattern of sickness. The premise is that frequent short absences are more disruptive — and more often a sign of an underlying issue — than occasional long ones.
The formula
Bradford Score = S² × D
where S = the number of separate spells of absence in the period, and D = the total days absent.
Same total days, very different scores:
- One 10-day absence: 1² × 10 = 10
- Five 2-day absences: 5² × 10 = 250
- Ten 1-day absences: 10² × 10 = 1,000
How employers use it
Most policies set thresholds — for example, 200 triggers a manager conversation, 400 a formal warning, 800 a final review. The score is usually calculated over a rolling 12-month window so old absences fall off the count.
Caveats
The Bradford Factor should not be the only trigger for action. It can disadvantage workers with disabilities or chronic conditions, and unmodified use risks discrimination claims. Most policies exclude pregnancy-related, disability-related, and long-term certified absences from the calculation.
How Luna HR handles this
Luna HR Leave Management — automatic Bradford Factor scoring