The Bradford Factor is S × S × D: the number of separate absences (spells) in the period, squared, multiplied by the total days absent. Most employers use a rolling 52 weeks. Four absences adding up to 8 days score 4 × 4 × 8 = 128; the same 8 days taken in one go score 1 × 1 × 8 = 8.
How to work it out
- Pick the period, usually the 52 weeks up to today.
- Count the separate spells of absence (S).
- Add up the total days absent (D). Some employers use hours instead of days for part-time staff.
- Multiply S by S, then by D.
Worked examples: 12 days of absence, three patterns
| Pattern | Calculation | Score |
|---|---|---|
| One absence of 12 days | 1 × 1 × 12 | 12 |
| Six absences of 2 days | 6 × 6 × 12 | 432 |
| Twelve absences of 1 day | 12 × 12 × 12 | 1,728 |
Because spells are squared, frequent short absences score far higher than one long absence. That is the point of the formula: short, unplanned absences are often the most disruptive.
Is there a legal Bradford Factor trigger score?
No. There are no legal rules on how or when absence should be reviewed, and Acas does not set Bradford scores. If you use trigger points (Acas calls them review points), Acas says you should:
- set them out clearly in your absence policy
- explain how an employee is flagged and that reaching one starts an absence review
- not use them to trigger disciplinary action automatically
Absences to treat carefully
Acas says that when you review absence you should consider whether it might be disability-related (and what reasonable adjustments could help), whether it is related to pregnancy or mental health, whether it was time off for dependants, and whether work caused it. Many employers leave pregnancy-related and disability-related absence out of the score.
Get every score worked out automatically. The Bradford Factor Absence Tracker (£10.99, Excel and Google Sheets) records each absence, calculates every employee's rolling 52-week score and flags your own trigger levels. It is also part of the UK HR & Absence Bundle.
Frequently asked questions
What is the Bradford Factor formula?
S × S × D, where S is the number of separate absences in the period and D is the total days absent. The period is usually a rolling 52 weeks.
What is a bad Bradford Factor score?
There is no official or legal threshold. Each employer sets its own review points in its absence policy.
Does Acas recommend the Bradford Factor?
Acas does not set Bradford scores. It says review points should be clear in your absence policy and should start an absence review, not automatic disciplinary action.
Should pregnancy or disability absence count in the Bradford Factor?
Acas says pregnancy-related and disability-related absence may need a different approach. Many employers exclude them from the score.
Sources
- Absence trigger points – Acas
- Measuring and monitoring absence from work – Institute for Employment Studies
This guide is general information, not legal or tax advice. Rules change; check the sources above.