The Bradford Factor is a formula that scores sickness absence by weighting frequent short absences more heavily than one long one. You square the number of separate absences (spells) in a rolling 52-week period and multiply by the total days off, so B = S × S × D.
Employers like the Bradford Factor because it puts a number on something managers already feel: a run of odd Mondays off disrupts a team more than one planned operation. Used carelessly, though, it punishes people with long-term conditions, pushes others to work while ill, and tells you nothing about why someone keeps calling in sick.
This guide gives you a Bradford Factor calculator, worked examples, the trigger points most policies use, and the checks that keep the score fair and lawful.
Table of Contents
How to calculate a Bradford Factor score
The formula has three parts:
- S (spells): the number of separate periods of absence in the last 52 weeks. Three days off in a row counts as one spell.
- D (days): the total number of days absent in the same period.
- B (Bradford Factor score): S × S × D.
Because spells are squared, the score climbs quickly when absences are frequent. Use a rolling 52-week window rather than a calendar year, so an absence in December doesn’t vanish on 1 January.
Bradford Factor calculator
Work out a score
Enter the absences from the last 52 weeks.
Score (S × S × D)
54
Informal conversation with the line manager
Bands follow the example trigger points below. Use your own policy’s figures.
Bradford Factor examples
Three employees each take 10 days off in a year. Their scores are very different:
| Employee | Pattern | Spells (S) | Days (D) | Score (S × S × D) |
|---|---|---|---|---|
| A | One 10-day absence after an operation | 1 | 10 | 10 |
| B | Five 2-day absences | 5 | 10 | 250 |
| C | Ten 1-day absences | 10 | 10 | 1,000 |
That gap is the whole point of the formula. Employee A's absence was planned and covered. Employee C's absences arrived without warning, ten times, and each one meant a manager reshuffling the day. The score reflects the disruption, not the days.
Bradford Factor trigger points
Most absence policies link scores to review stages. There is no legal standard, so set your own and write them into your absence policy. A common pattern looks like this:
| Bradford Factor score | Typical action |
|---|---|
| 0 to 49 | No action |
| 50 to 124 | Informal conversation with the line manager |
| 125 to 399 | Formal absence review meeting |
| 400 to 649 | Second formal review, possibly with an occupational health referral |
| 650 and above | Final review under the capability or absence procedure |
Treat these as review points, not punishments. Acas guidance on absence trigger points says employers should not use them to start disciplinary action automatically. A trigger should start a conversation about why someone is off.
Where the Bradford Factor backfires
The Bradford Factor measures a pattern. It does not explain it, and that's where most problems start.
It can discriminate
Someone with a disability, a long-term condition or pregnancy-related illness can rack up spells quickly. Under the Equality Act 2010 you may need to adjust or discount that absence. Acas suggests options such as not counting disability-related absence towards triggers, or raising the trigger level for that person. If your policy applies scores blindly, you're carrying legal risk.
It pushes people into presenteeism
When people know every short absence costs them points, many come in when they shouldn't. They work slowly, make mistakes and pass illness on to colleagues. You swap a visible cost for a hidden one, which our guide to presenteeism explains in more detail.
It hides the cause
A high score might mean a caring responsibility, a bad relationship with a manager, a workload problem or early burnout. Our post on the main causes of absenteeism shows how often the reason sits in the job rather than the person. A number can't tell you which.
How to use the Bradford Factor fairly
If you use the Bradford Factor, these steps keep it useful rather than harmful:
- Write it into your absence policy, including the trigger points and what happens at each stage, so nobody is surprised.
- Record disability and pregnancy-related absence separately and agree adjustments with the person.
- Hold a return to work conversation after every absence, so patterns are discussed while they're small.
- Use the score to start a conversation, never as the only reason for a warning.
- Look at team patterns as well as individuals. If one team has far higher scores than the rest, the problem is probably the team, the workload or the manager.
That last point matters most. Absence is often the late signal of disengagement, stress or poor management. Asking people regularly and anonymously how they're doing tells you about those problems months before they show up as sick days. Wotter is one example of a tool that does this, but a simple pulse survey run well will tell you a lot.
Absence also feeds straight into turnover, because people who are struggling often leave. Our employee turnover cost calculator shows what that costs.
Frequently asked questions
What is a good Bradford Factor score?
A score under 50 is usually seen as normal attendance and needs no action. Anything above that depends on your own absence policy, because there is no legal standard.
Is 250 a high Bradford Factor score?
In many policies 250 sits in the formal review range. It could be five 2-day absences in a year, so it's worth a conversation about the cause rather than an automatic warning.
How long does a Bradford Factor score last?
Most employers use a rolling 52-week period, so each absence drops out of the score a year after it happened.
Is the Bradford Factor legal in the UK?
Yes, but you must apply it fairly. Disability and pregnancy-related absence may need to be discounted or treated differently to avoid discrimination under the Equality Act 2010.
Why is it called the Bradford Factor?
It's named after the University of Bradford's School of Management, where the research behind it was carried out in the 1980s.
Use the score to ask better questions
The Bradford Factor is a quick way to spot disruptive absence patterns, and the calculator above will give you a score in seconds. Its value lies in the conversation it starts. Pair it with fair trigger points, proper adjustments and regular, honest feedback from your people, and you'll fix the causes of absence rather than just counting it.
General summary, not legal advice. For your own situation, check Acas guidance or take legal advice.
