What is the Bradford Factor, and how UK HR teams use it
The Bradford Factor is a simple formula that turns an employee’s absence record into a single score, weighted so that frequent short absences count for far more than one long absence of the same total length. UK HR teams use it to spot patterns of unplanned absence and decide when to start a supportive conversation. This guide explains the formula, works through real examples, shows how trigger points are set, and covers the legal cautions that most explanations leave out.
The formula
Bradford Factor = S² × D
S = the number of separate spells (instances) of absence in the period
D = the total number of days absent in the period
How the Bradford Factor works
The score is worked out over a set period, almost always a rolling 52 weeks. You count how many separate spells of absence an employee has had, square that number, then multiply by the total days they were absent.
The squaring is the whole point. It means the number of separate absences drives the score far more than the total days off. An employee who is absent once for two weeks scores very low. An employee off for odd single days throughout the year, adding up to the same two weeks, scores dramatically higher. The formula is built on the view that frequent, unpredictable absences are harder for a business to plan around and cover than one longer, often planned, absence.
Worked examples: why frequency matters more than length
The clearest way to understand the Bradford Factor is to see the same ten days of absence scored four different ways.
| Absence pattern | Spells (S) | Days (D) | Calculation | Score |
|---|---|---|---|---|
| One absence of 10 days | 1 | 10 | 1² × 10 | 10 |
| Two absences, 5 days each | 2 | 10 | 2² × 10 | 40 |
| Five absences, 2 days each | 5 | 10 | 5² × 10 | 250 |
| Ten absences, 1 day each | 10 | 10 | 10² × 10 | 1,000 |
Every row is ten days of absence. The scores range from 10 to 1,000. That hundredfold difference is the Bradford Factor doing exactly what it was designed to do: flag the employee with ten separate single-day absences as a much bigger operational concern than the employee who took one continuous fortnight off.
How UK HR teams set trigger points
A Bradford Factor score means nothing on its own. Its value comes from the trigger points an organisation sets in its absence policy. When a score crosses a threshold, it prompts a defined action, usually starting with a supportive conversation rather than a penalty.
There is no legal or national standard for these thresholds. Each employer sets its own. The following are examples of thresholds in common use, not a rule to copy:
- Under 50: low concern, no action needed
- 50 to 124: an informal check-in with the employee
- 125 to 399: a formal review under the absence policy
- 400 and above: a serious concern warranting a structured process
The right thresholds depend on your sector, your typical absence levels and the size of your team. A frontline operation covering shifts may set lower triggers than an office where work can be picked up later. The important thing is that the thresholds are written down, applied consistently, and communicated to staff so nobody is caught by surprise.
To put scores in context, it helps to know the national picture. According to the Office for National Statistics, UK workers lost an average of 4.4 days to sickness in 2025, with an estimated 148.8 million working days lost in total. The CIPD’s 2025 Health and Wellbeing at Work report, based on a survey of more than 1,100 employers, put the figure higher at 9.4 days per employee, the highest level it has recorded in over a decade. Whichever measure you use, absence is rising, which is why consistent monitoring matters.
What the Bradford Factor is good at, and where it falls short
Used well, the Bradford Factor gives HR teams an objective, consistent way to identify absence patterns that would otherwise be easy to miss. It removes gut feeling from the decision about when to act, and it treats every employee by the same measure. For managers juggling large teams, that consistency is genuinely useful.
It is not a perfect tool, and treating a score as an automatic verdict is where employers get into trouble. A high score can reflect a genuine underlying health condition rather than a conduct problem. Someone with a chronic illness that flares up unpredictably will accumulate a high score through no fault of their own. The formula also takes no account of the reason for an absence, only its shape.
The correct approach is to use the score as a prompt for a conversation, not as evidence of wrongdoing. The conversation is where you find out what is actually going on, whether support or an adjustment is needed, and whether the absences are connected. A good absence management software system calculates Bradford scores automatically and flags triggers, but the judgement about what to do next always stays with a person.
The legal cautions most guides skip
This is the part that matters most, and the part that many Bradford Factor explanations leave out entirely. Applying the formula mechanically can expose an employer to discrimination claims.
Disability-related absence. Under the Equality Act 2010, disability is a protected characteristic. Counting disability-related absences towards a Bradford score, and then applying a sanction, can amount to discrimination arising from disability. Employers have a duty to make reasonable adjustments, which may include discounting disability-related absences from the calculation or raising the trigger point for an affected employee.
Pregnancy and maternity. Pregnancy-related absence must not be counted towards absence triggers. Doing so risks a claim of pregnancy and maternity discrimination, which does not require a comparator and can be costly to defend.
Consistency and process. Even where an absence is not related to a protected characteristic, you must apply your policy consistently and follow a fair procedure. A score should open a process, never replace one.
None of this means the Bradford Factor cannot be used. It means it must be used with judgement, with clear carve-outs for protected absences, and always alongside a fair process. The score identifies where to look. It never decides the outcome.
Making the Bradford Factor work in practice
The Bradford Factor is only as good as the absence data behind it. If spells and days are recorded inconsistently across managers or sites, the scores will be unreliable and unfair. This is where accurate, centralised record-keeping earns its place. Capturing every absence the same way, in one system, means scores are calculated on a consistent basis for everyone.
That accuracy also depends on clean attendance data feeding in from the start, which is where reliable time and attendance software makes the difference. When clocking, absence and holiday data all live in one place, Bradford scores update automatically on a rolling basis, triggers flag themselves, and managers spend their time on the conversation rather than the calculation.
If you would like to see how automated Bradford Factor scoring and absence triggers work in practice, our team can walk you through it on a short call.
See automated absence scoring in action
