What is the Bradford Factor? A UK guide

The Bradford Factor is a simple formula that scores the disruption caused by absence, weighting lots of short, frequent absences far more heavily than the occasional long one. Here is the formula, some worked examples, the trigger bands people use, and the fairness traps to avoid.

Last reviewed July 2026 · General guidance, not legal advice.

What the Bradford Factor measures

The Bradford Factor is a way of turning someone’s absence record into a single number that reflects how disruptive that absence has been — not just how many days were lost. The idea, credited to research associated with the Bradford University School of Management, is that frequent short absences (a day here, a day there) are harder to plan around and cover than one longer, planned block. The formula deliberately punishes the former.

The formula: B = S² × D

The score is worked out over a rolling 52-week period using two figures:

S — the number of separate absence spells (instances), no matter how long each one is.
D — the total number of days absent across all those spells.

You then multiply the number of spells squared by the total days: B = S² × D. Squaring the spells is the whole point — it makes many separate absences score much higher than the same days taken in one go.

Worked examples

These three examples all involve 10 total days off, but the scores differ wildly:

Pattern	Spells (S)	Days (D)	Calculation	Score
One 10-day illness	1	10	1² × 10	10
Two 5-day spells	2	10	2² × 10	40
Five 2-day spells	5	10	5² × 10	250

The same ten lost days score 10 as a single spell but 250 when scattered across five — twenty-five times higher, purely because of how often the person was absent. You can work out a score instantly with our Bradford Factor calculator rather than doing the sums by hand.

Typical trigger bands

There is no official or legal set of thresholds — each employer sets its own. That said, widely-cited templates often use points bands like these as a starting point:

51 points — an informal review or an early return-to-work conversation.
201 points — a more formal discussion and possibly a first warning under your absence procedure.
401 points — treated as a serious concern warranting further formal action.

Treat these as illustrative only. Whatever bands you adopt, publish them, apply them the same way for everyone, and use a trigger as a prompt to talk — never as automatic discipline. Always look at the reasons behind a score before acting.

Pros and cons

Used well, the Bradford Factor is a simple, consistent way to spot patterns. But it has real limits:

Pro: it is objective and easy to calculate, and it highlights frequent short-term absence that headline day-counts can hide.
Pro: a shared formula and published bands help managers act consistently rather than on gut feel.
Con: it can feel punitive and may push people to come in when genuinely unwell (presenteeism).
Con: a single score strips out context — the reason for the absence matters far more than the number.

Fairness and legal cautions

The score is only a tool. How you use it is where the legal risk lies:

Disability discrimination. Under the Equality Act 2010 you may need to make reasonable adjustments, which can include discounting disability-related absence from the score. Applying a blanket trigger to a disabled employee can be discriminatory.
Pregnancy and maternity. Pregnancy-related absence should usually be excluded from the calculation — counting it towards a trigger can amount to unlawful discrimination.
Data protection. Absence and health data is special-category personal data. Store it securely, limit who can see it, and be clear with staff about how scores are used.

In short: use the score to start a fair, human conversation, keep records of your reasoning, and take advice on individual cases. This is general guidance, not legal advice — check gov.uk and Acas for your circumstances.

How to track it

The Bradford Factor is only useful if the underlying absence data is accurate and up to date. For a manual approach, our free absence tracker (Excel) has the Bradford Factor built in, so a score appears as you log each spell. If you would rather not maintain a spreadsheet, Rotaleave’s reports compute each person’s Bradford Factor automatically from their real absence records, so nothing has to be re-keyed.

Common questions

What is a good or bad Bradford Factor score?

There is no legal figure — every employer sets its own trigger points. Many published templates use bands such as 51 for an informal review, 201 for further action and 401 for something more serious, but these are only examples. Whatever you pick, write it down, apply it consistently, and treat a high score as a prompt for a conversation rather than automatic discipline.

Why does the score square the number of absences?

Squaring the number of separate spells (S) is what makes the Bradford Factor weight frequent short absences far more heavily than one long one. Ten days off in a single block scores 10, but the same ten days taken as five separate two-day spells scores 250. The formula assumes scattered absences are more disruptive to cover and planning.

Should every absence count towards the score?

No. Most employers exclude absences related to disability, pregnancy or maternity, and other protected reasons, and often authorised leave such as jury service or bereavement. Counting disability-related absence towards a trigger can amount to discrimination, so take advice before acting on any score.

Is the Bradford Factor a legal requirement?

No. It is a management tool, not a law. Nothing requires you to use it, and using it does not override your duties under the Equality Act 2010 or data protection law. It is a way to spot patterns fairly and consistently, not a substitute for judgement.