Bradford Factor Calculator
The Bradford Factor is S² × D, where S is the number of separate absence spells and D is the total number of days absent, usually measured over a rolling 52 weeks. Frequent short absences raise the score far more than one long absence.
Enter the number of absence spells and total days absent to calculate the score instantly. No email is required. Use the result as a review prompt alongside your policy and the employee's individual circumstances.
Bradford Factor Calculator
Enter absence data for a rolling 12-month period
Separate instances of absence, not individual days
Total working days absent across all spells
Your result will appear here immediately.
Enter both values above. No email address is required.
Illustrative Bradford Factor review bands
There is no statutory or universal scale. Set and document review points that fit your organisation.
| Score range | Illustrative band | Review prompt |
|---|---|---|
| 0 – 49 | Lower | Follow your normal absence process |
| 50 – 124 | Review | Check the pattern and individual context |
| 125 – 399 | Elevated | Consider a supportive policy review |
| 400 – 649 | Higher | Check protected absence and adjustments |
| 650+ | Highest | Escalate for careful HR review, not automatic sanction |
What is the Bradford Factor?
The Bradford Factor (also called the Bradford Formula or Bradford Index) is a widely used HR metric that measures the impact of employee absences on an organisation. It was developed at the Bradford University School of Management and is based on the principle that frequent, short-term absences are more disruptive to a business than fewer, longer absences.
For example, an employee who takes ten separate single-day absences causes significantly more disruption than an employee who takes one ten-day absence. Each short absence requires last-minute cover, work redistribution, and management time — multiplied across every occurrence.
How the Bradford Factor formula works
The formula is:
B = S × S × D
B = Bradford Factor score
S = number of separate absence spells in a rolling 12-month period
D = total number of days absent in the same period
The critical detail is that S is squared. This means the number of separate absence instances has a much greater impact on the score than the total number of days. Two employees can have the same number of days off but wildly different Bradford Factor scores depending on how those days are distributed.
Worked example
Consider two employees who have both been absent for 10 days over 12 months:
- Employee A — 1 absence spell of 10 days: 1 × 1 × 10 = 10
- Employee B — 10 separate single-day absences: 10 × 10 × 10 = 1,000
Employee B scores 100 times higher despite the same total days absent. The Bradford Factor flags Employee B's pattern as far more disruptive.
How to use Bradford Factor scores
The Bradford Factor is a review prompt, not a disciplinary tool. A high score should prompt a conversation, not an automatic penalty. A sensible process is to:
- Set clear review points — define your own thresholds in the absence policy and communicate them to all staff.
- Monitor over a rolling 12-month period — calculate scores using the previous 12 months, not the calendar year.
- Investigate context — when an employee hits a threshold, have a supportive conversation to understand the reasons behind their absences.
- Account for protected absence — consider disability-related and pregnancy-related absence, reasonable adjustments, and other protected circumstances before relying on a score.
- Apply consistently — use the same thresholds and processes for every employee to avoid claims of discrimination.
Limitations to be aware of
The Bradford Factor is a useful tool but it has limitations that every employer should understand:
- Disability discrimination risk — employees with chronic conditions (e.g. migraines, IBS, endometriosis) may have frequent short absences that inflate their score. Under the Equality Act 2010, employers must make reasonable adjustments and should consider excluding disability-related absences.
- No context — the formula treats all absences equally. A genuine flu and a suspicious post-weekend absence both count the same.
- Presenteeism risk — employees aware of the formula may come to work while unwell to avoid triggering thresholds, which can spread illness and reduce productivity.
- Not a standalone tool — the Bradford Factor should be one component of a broader absence management approach, never the sole basis for disciplinary action.
Best practices for UK employers
- Document your policy — include the Bradford Factor, trigger thresholds, and the process that follows in your company absence policy.
- Train managers — ensure line managers understand the formula, what scores mean, and how to conduct supportive absence conversations.
- Use return-to-work interviews — pair the Bradford Factor with return-to-work interviews to get a fuller picture of absence patterns.
- Automate the calculation — manual tracking in spreadsheets is error-prone and time-consuming. Leave management software calculates Bradford Factor scores automatically as absence records are updated.
- Review thresholds annually — what works for a 10-person team may not suit a 100-person organisation. Review your trigger points as your business grows.
Guidance checked 22 August 2026
Acas says absence review points should not automatically trigger disciplinary action and that employers should consider adjustments for disability-related absence.
This calculator provides general information, not legal advice.
How to calculate the Bradford Factor
Count the separate spells of absence in the period (S), square that number, then multiply by the total working days absent (D). The examples below show why repeated short absences produce much higher scores than a single longer one.
| Absence pattern | Spells (S) | Days (D) | S × S × D | Score |
|---|---|---|---|---|
| One 10-day absence | 1 | 10 | 1 × 1 × 10 | 10 |
| Two 2-day absences | 2 | 4 | 2 × 2 × 4 | 16 |
| Five 1-day absences | 5 | 5 | 5 × 5 × 5 | 125 |
| Five absences totalling 10 days | 5 | 10 | 5 × 5 × 10 | 250 |
| Ten 1-day absences | 10 | 10 | 10 × 10 × 10 | 1,000 |
The same 10 days off can score 10 or 1,000 depending on how the absence was spread. For a fuller explanation of where the formula came from, read our guide to the Bradford Factor explained.
What to count before you calculate
- Working days only. Leave out weekends, bank holidays and days the employee was not contracted to work, so part-time staff are not penalised.
- Continuous absence is one spell. Sickness on a Friday and the following Monday, with no working day back in between, is normally a single spell.
- A rolling period. Use the 52 weeks up to today rather than the calendar or leave year.
- Sickness absence, not protected leave. Holiday, maternity, paternity, adoption, time off for dependants and other statutory leave are not sickness spells. Record pregnancy-related sickness separately and consider disability-related absence and reasonable adjustments under the Equality Act 2010 before relying on a score.
Treat a score as a prompt for a supportive conversation, not an automatic sanction. Our guide to sickness absence trigger points covers how to set and apply review points fairly, and Statutory Sick Pay rules explain what eligible staff are paid while off.
Track it automatically
In Leavely, each employee's Bradford Factor is worked out from their recorded sickness over a rolling 365 days. It uses their own working pattern and your bank holidays, so non-working days are not counted and absences either side of a weekend are joined into one spell. See how it fits into absence management software for UK teams.
Bradford Factor questions
What is a good or bad Bradford Factor score?
There is no official good or bad score in UK law. Many organisations treat a score under 50 as no cause for concern and set review points somewhere between 50 and 650, but you should choose and document your own review points in your absence policy and apply them consistently.
Does the Bradford Factor include weekends?
Normally no. D should count the working days the employee was due to work and missed, so weekends, bank holidays and other non-working days are left out. A Friday absence followed by a Monday absence is usually treated as one continuous spell rather than two.
What time period should the Bradford Factor cover?
Most employers use a rolling 52-week (12-month) period that ends on the day of the calculation. A rolling period avoids scores resetting at the start of a calendar or leave year.
Is the Bradford Factor legal in the UK?
Yes. Employers can use it to monitor sickness absence, but the score must not be applied automatically. Disability-related absence, pregnancy-related sickness and other protected circumstances need separate consideration, and decisions should follow a fair process with a supportive conversation first.
Should disability-related absence count towards the score?
It needs careful handling. Under the Equality Act 2010 employers must consider reasonable adjustments, which can include discounting disability-related absence or setting a different review point for that employee. Pregnancy-related sickness should be recorded separately and not used against the employee.
Can I use the Bradford Factor for part-time staff?
Yes, as long as D counts only the days the person was contracted to work. Counting non-working days would inflate a part-time employee’s score and treat them less favourably than a full-time colleague.