Bradford Factor Explained: How to Calculate and Use It
The Bradford Factor is a formula used by HR departments across the UK to measure the impact of employee absences. It's designed to highlight patterns of frequent, short-term absences — which are typically more disruptive to a business than longer, planned absences.
The Bradford Factor formula
The formula is straightforward:
B = S × S × D
B = Bradford Factor score
S = number of separate absence spells (instances)
D = total number of days absent
The key insight is that S is squared. This means frequent short absences produce a much higher score than a single long absence — even when the total days absent are the same.
Bradford Factor examples
Consider two employees who have both been absent for 10 days in a year:
| Employee | Absences (S) | Total days (D) | Bradford Factor |
|---|---|---|---|
| Alice — 1 long absence | 1 | 10 | 1 × 1 × 10 = 10 |
| Bob — 10 single-day absences | 10 | 10 | 10 × 10 × 10 = 1,000 |
Alice scores 10, Bob scores 1,000 — despite both taking 10 days off. The Bradford Factor highlights that Bob's pattern of frequent single-day absences is far more disruptive to business operations.
Bradford Factor trigger point thresholds
There are no legally mandated trigger points — each organisation sets its own. However, these thresholds are commonly used across UK businesses:
| Score | Level | Typical action |
|---|---|---|
| 0–49 | Low | No action required |
| 50–124 | Medium | Informal discussion with manager |
| 125–399 | High | Formal review meeting |
| 400–649 | Very high | Written warning |
| 650+ | Critical | Final warning or disciplinary |
Advantages of the Bradford Factor
- Objective measurement — removes subjectivity from absence discussions.
- Highlights patterns — identifies employees with frequent short-term absences that disrupt team productivity.
- Simple to calculate — the formula is straightforward and easy to explain to employees.
- Widely recognised — most UK employees and unions understand the Bradford Factor.
Limitations and criticisms
- Disability discrimination risk — employees with chronic conditions may have frequent short absences that inflate their score. Employers must make reasonable adjustments under the Equality Act 2010.
- Doesn't distinguish reasons — a genuine illness and a suspicious Monday absence both count the same.
- Can discourage reporting — employees may come to work ill to avoid triggering thresholds, spreading illness to colleagues.
- Should not be used alone — the Bradford Factor should be one tool among many, not the sole basis for disciplinary action.
Best practices for using the Bradford Factor
- Document your policy — include the Bradford Factor and trigger points in your absence policy. Make sure all employees understand how it works.
- Apply it consistently — use the same thresholds and process for everyone to avoid discrimination claims.
- Consider context — always investigate the reasons behind high scores before taking action.
- Exclude protected absences — disability-related absences, maternity leave, and other protected absences should be excluded from the calculation.
- Use a rolling 12-month period — calculate scores over the last 12 months, not the calendar year.
- Automate the calculation — manual tracking is error-prone. Use leave management software to calculate scores automatically.
How Leavely calculates the Bradford Factor automatically
Leavely automatically calculates the Bradford Factor for every employee based on their sick leave records. On each employee's profile, managers can see:
- Current Bradford Factor score (rolling 12 months)
- Number of separate absence spells
- Total days absent
- Full sick leave history with dates
No spreadsheets, no manual counting — the score updates automatically as leave records are added.