The formula
B = S × S × D, where S is the number of separate spells of absence and D is the total days absent, both over the last 12 months (or 52 weeks).
A worked example
One absence of 10 days: 1 × 1 × 10 = 10. Ten absences of 1 day: 10 × 10 × 10 = 1,000. Same days off, very different scores - that's the point of the formula.
Trigger points
Employers set their own thresholds in their absence policy for when to have a conversation or take further steps. Write yours down and apply them consistently.
Use it fairly
Treat absence linked to a disability, pregnancy or other protected reasons carefully - a score is never the whole story. Record fit notes and return-to-work conversations alongside it.