Bradford Factor Calculator
Calculate Bradford Factor scores from absence dates. See trigger levels, understand the formula, and get practical guidance on managing short-term absence for full-time and part-time workers.
Separate periods of absence in a 52-week period
Total working days absent across all occasions
Results
Enter the number of absence occasions and total days absent to calculate the Bradford Factor score.
What Is the Bradford Factor?
The Formula
The Bradford Factor is a widely used HR formula that measures the impact of short-term absence on a business. It was developed at the Bradford University School of Management and is based on the principle that frequent, short absences are more disruptive than fewer, longer ones.
B = S x S x D
Where S = number of separate absence occasions and D = total working days absent
| Example | S | D | Score |
|---|---|---|---|
| 1 absence of 10 days | 1 | 10 | 10 |
| 5 absences of 2 days each | 5 | 10 | 250 |
| 10 absences of 1 day each | 10 | 10 | 1,000 |
All three examples involve 10 total days of absence, but the scores range from 10 to 1,000. The squaring of S means that frequent single-day absences generate a significantly higher score than one longer absence of the same total duration.
Part-Time Workers
When calculating the Bradford Factor for part-time employees, only count the days the employee was contracted to work. If someone works Monday to Wednesday and is absent for a full week (Monday to Friday), they have missed 3 working days, not 5. The Part-Time Workers (Prevention of Less Favourable Treatment) Regulations 2000 require that part-time workers are not treated less favourably than full-time colleagues, so trigger thresholds should be applied consistently regardless of working pattern.
Common Trigger Thresholds
There is no legal requirement to use specific trigger points, and the right thresholds depend on your organisation. A common framework used by UK employers looks like this:
| Score | Typical Response |
|---|---|
| 0 - 50 | No action required |
| 51 - 199 | Informal discussion / return-to-work meeting |
| 200 - 399 | Written warning / formal absence review |
| 400+ | Final written warning / capability procedure |
ACAS Guidance
ACAS recommends that trigger points should prompt a conversation, not automatic disciplinary action. There is no legal requirement to use the Bradford Factor, and it should never be the sole basis for a decision about an employee's employment. Employers should always consider the reasons behind absences, whether a disability under the Equality Act 2010 may be a factor, and whether reasonable adjustments are needed before taking formal steps.
Limitations to Be Aware Of
The Bradford Factor is a useful tool for identifying patterns, but it has well-known limitations. It does not distinguish between genuine illness and avoidable absence. It can unfairly penalise employees with disabilities or chronic conditions, which may amount to disability discrimination under the Equality Act 2010. It also ignores context entirely: a single score tells you nothing about why someone was absent. Many employers use it alongside other absence data rather than as a standalone measure, and some exclude disability-related absences from the calculation entirely.
Need Help Managing Absence?
The Bradford Factor is a starting point, not the whole picture. If you need help building an absence management policy, handling a tricky case, or supporting a manager through the process, we can help.
Book a Free ConsultationThis calculator is provided for general guidance only and does not constitute legal or professional advice. Results are based on the information you provide and common Bradford Factor methodology. Individual circumstances, contractual terms, and the Equality Act 2010 may affect how absence data should be interpreted and acted upon. Rebox HR accepts no liability for decisions made based on these results. For advice specific to your situation, please contact us.
How the Bradford Factor is Calculated
The Bradford Factor formula is simple, but the maths reveals something important about how short, repeated absences affect a business.
Bradford Factor Formula
B = S2 × D
- S
- Number of separate absence occurrences in a rolling 12-month period
- D
- Total days absent across all those occurrences
The key insight is that frequency is squared. Two employees with the same total number of days off can produce very different scores, because the formula weights disruption caused by repeated short absences much more heavily than one long one.
Bradford Factor Examples
The same 10 total sick days can produce scores ranging from 10 to 1,000 depending on how they fall. This is why the Bradford Factor is useful for spotting absence patterns that a simple day count misses.
| Absence pattern | Occurrences (S) | Total days (D) | Score |
|---|---|---|---|
| One long absence of 10 days | 1 | 10 | 10 |
| Two absences of 5 days each | 2 | 10 | 40 |
| Five absences of 2 days each | 5 | 10 | 250 |
| Ten absences of 1 day each | 10 | 10 | 1,000 |
Typical UK Trigger Levels
Most UK employers use four trigger levels, each prompting a specific management conversation. These numbers are conventions, not fixed rules. Your absence policy should document your chosen thresholds and the process that follows. Under the Equality Act 2010, disability-related absence should normally be discounted from the calculation.
51 points
Informal return-to-work conversation
A private chat with the line manager, usually on the first day back, to understand what happened and whether any support is needed.
201 points
Formal absence review meeting
A documented meeting reviewing the pattern of absence, any underlying cause, and a written agreement on what improvement looks like.
401 points
Written warning under the capability procedure
A formal stage of the capability procedure, with the right to be accompanied, clear improvement targets, and a review period.
601 points
Dismissal consideration
Never automatic. A proper capability hearing must follow, with full investigation, reasonable adjustments considered, and the right of appeal.
Bradford Factor FAQs
- What is the Bradford Factor?
- The Bradford Factor is a score that measures the impact of short, frequent employee absences on a business. It was developed at the University of Bradford School of Management in the 1980s, based on the observation that several short absences disrupt operations more than one long absence. UK employers use it as a trigger for informal conversations, formal reviews and capability procedures.
- How is the Bradford Factor calculated?
- The Bradford Factor formula is S squared multiplied by D, where S is the number of separate absence occurrences in a rolling period (usually 12 months) and D is the total number of days absent across all those occurrences. So one 10-day absence scores 10 points (1 x 1 x 10), but 10 separate 1-day absences score 1,000 points (10 x 10 x 10). The formula penalises frequency far more heavily than total duration.
- What counts as a Bradford Factor score of concern?
- Most UK employers set Bradford Factor trigger levels at 51, 201, 401 and 601 points, each triggering a progressively more formal response. 51 points typically triggers an informal return-to-work conversation. 201 points triggers a formal absence review. 401 points triggers a written warning under the capability procedure. 601 points is usually the threshold for considering dismissal, though no trigger should result in an automatic outcome.
- Is the Bradford Factor legal in the UK?
- Yes, the Bradford Factor is legal as a management tool in the UK, but it cannot be used mechanically. Employment tribunals will set aside any dismissal based solely on a Bradford score, and the Equality Act 2010 requires employers to make reasonable adjustments for disability-related absence, which should normally be discounted from Bradford calculations. Use it as an indicator to start a conversation, never as a substitute for proper investigation and due process.
- How do I calculate Bradford Factor scores for my team?
- Enter each employee's separate absence occurrences and durations into the calculator at the top of this page. The tool returns the score, the trigger band, and suggested actions. If you manage more than a handful of employees, we recommend using HR software to track absence automatically and alert you when scores cross a trigger threshold.
- What is a Bradford Factor trigger level?
- A trigger level is the Bradford Factor score at which a specific management action is expected. UK employers typically use four bands: 51 (informal chat), 201 (formal review), 401 (written warning) and 601 (dismissal consideration). Your absence policy should document your trigger levels and the process that follows, so employees know what to expect and managers apply the scheme consistently.
- Does disability-related absence count towards the Bradford Factor?
- Under the Equality Act 2010, UK employers have a duty to make reasonable adjustments for employees with a disability. In almost all cases, this means discounting disability-related absence from the Bradford Factor calculation, or setting a higher trigger threshold for affected employees. Counting disability absence the same as unrelated sickness is one of the fastest ways to lose an employment tribunal claim.
- What is the difference between the Bradford Factor and a Bradford Score?
- The terms Bradford Factor and Bradford Score are used interchangeably in the UK. Both refer to the same calculation: S squared multiplied by D. Some sources also call it the Bradford Index, Bradford Formula, or Bradford Points. They all describe the same metric.
Need Help Managing Absence?
Rebox HR helps UK SMEs design fair absence policies, set the right trigger levels, and handle difficult absence cases without tribunal risk. Our CIPD-qualified consultants can support you on a retained or pay-as-you-go basis.