Bradford Factor Calculator

What is the Bradford Factor?

The Bradford Factor is a simple formula used by some organisations to measure the impact of employee sickness absence. It gives a higher score to frequent short absences than to occasional long absences, on the assumption that frequent disruption is more damaging to productivity and scheduling.

It was originally developed at the University of Bradford School of Management in the UK and is now widely referenced in HR policies, especially in contact centres, retail, and other high‑volume environments.

Bradford Factor formula

An “instance” is one continuous spell of absence, regardless of how many days it lasts. For example, if an employee is off sick Monday–Wednesday, returns Thursday, and is off again the following Monday, that counts as:

• S = 2 instances (two separate spells)
• D = 4 days absent (3 days + 1 day)

Worked examples

Example 1 – one long absence

• Review period: 12 months
• 1 absence instance of 20 days
• S = 1, D = 20

Bradford Factor: \( B = 1^2 \times 20 = 20 \)

Example 2 – many short absences

• Review period: 12 months
• 10 absence instances of 2 days each (20 days total)
• S = 10, D = 20

Bradford Factor: \( B = 10^2 \times 20 = 1{,}000 \)

Both employees have lost 20 days, but the second has a score 50 times higher because of the number of separate spells. This is why the Bradford Factor is controversial and should be interpreted with care.

Typical Bradford Factor thresholds

There is no universal standard for what counts as a “high” Bradford Factor score. Organisations usually define their own trigger points in consultation with HR, managers, and (where applicable) unions.

Common example bands (for illustration only) include:

• 0 – 49: Low or no concern – usually no action.
• 50 – 199: Monitor – informal conversation or closer tracking.
• 200 – 399: Formal review – may trigger a formal absence review meeting.
• 400+: Serious concern – may trigger higher‑level review or disciplinary process.

Use the “Custom trigger thresholds” section in the calculator to match these bands to your own policy, or to test how changing thresholds would affect your workforce.

How to use this Bradford Factor calculator

1. Choose the review period. Decide which period you want to analyse (e.g. the last 52 weeks, calendar year, or rolling 12 months) and enter the number of working days in that period.
2. Count absence instances (S). For the employee, count how many separate spells of sickness absence they have had in that period. Each continuous spell counts as one instance, regardless of length.
3. Sum total days absent (D). Add up the number of working days lost across all instances in the same period.
4. Click “Calculate Bradford Factor”. The tool applies the formula \( B = S^2 \times D \), shows the score, and places it into an impact band based on your thresholds.
5. Interpret the result in context. Use the score as one input into a broader conversation, not as an automatic decision.

Strengths and limitations

Potential benefits

• Simple, transparent formula that is easy to explain.
• Highlights patterns of frequent short‑term absence that might otherwise be missed.
• Can support consistent application of absence policies across teams.

Key limitations and criticisms

• No context. The Bradford Factor does not consider the reason for absence, underlying health conditions, disability, pregnancy‑related illness, or workplace factors such as workload and stress.
• Risk of discrimination. If used rigidly, it can disproportionately penalise employees with chronic or fluctuating conditions, neurodivergence, or caring responsibilities.
• Perverse incentives. Employees may feel pressured to attend work when unwell (“presenteeism”) or to avoid reporting short illnesses.

Many HR experts therefore recommend using the Bradford Factor only as a flag for further discussion, not as an automatic trigger for disciplinary action.

Good practice when using the Bradford Factor

• Always review the underlying reasons for absence before taking any action.
• Make reasonable adjustments for disability and long‑term health conditions.
• Apply the policy consistently and document how thresholds are used.
• Train managers to have supportive, open conversations about attendance and wellbeing.
• Regularly review whether the metric is achieving its intended purpose.

FAQ

Is the Bradford Factor fair?

It depends how it is used. As a rough indicator of patterns that may need attention, it can be useful. As a rigid, automatic trigger for sanctions, it is often considered unfair and potentially discriminatory. Fair use requires context, judgement, and adjustments for individual circumstances.

What review period should I use?

Common choices are the last 52 weeks, the current holiday year, or a rolling 12‑month period. The important thing is to be consistent and clear in your policy about which period you use and how often scores are reviewed.

Can I use the Bradford Factor for part‑time staff?

Yes, but you should base D on their working days, not full‑time equivalents. For example, if someone works 3 days per week, a full year might be around 156 working days instead of 260. Make sure your policy explains how you handle part‑time and shift patterns.

Should I include authorised leave or only sickness?

The Bradford Factor is usually applied only to sickness absence and sometimes unauthorised absence, not to annual leave, parental leave, or other approved time off. Your HR policy should define exactly which absence types are included.

Can I use this calculator for a whole team?

Yes. You can run the calculation separately for each employee and compare scores, but always interpret them alongside qualitative information, job roles, and individual circumstances rather than ranking people purely by score.

This tool is for information and education only and does not constitute legal or HR advice. Always consult your HR team and, where appropriate, legal counsel when designing or applying absence management policies.