The Bradford Factor formula is: S squared multiplied by D, where S is the number of absence spells in a rolling period (typically 52 weeks) and D is the total number of days absent in that same period. The squaring of S means that the frequency of absences has a disproportionate effect on the score. For example, one absence of 10 days gives a score of 10 (1 x 1 x 10). Two absences of 5 days each gives a score of 20 (2 x 2 x 5). Five absences of 2 days each gives a score of 50 (5 x 5 x 2). Ten single-day absences give a score of 100 (10 x 10 x 1). This progression reflects the research finding that unplanned frequent absences create significantly more operational disruption than the raw number of days lost would suggest.
Bradford Factor thresholds vary by organisation, but common trigger points are: below 100 - normal absence requiring routine management; 100 to 199 - first formal review meeting; 200 to 399 - second formal review or written warning; 400 and above - final stage of the process. These thresholds should be set in the organisation's absence management policy and communicated clearly to all employees. Critically, the thresholds should not operate as automatic disciplinary sanctions - they are triggers for review conversations. The purpose of those conversations is to understand the pattern, check for underlying disability or health conditions that require different handling, and agree a management plan.
The Bradford Factor has important limitations that HR teams must understand. First, it does not distinguish between types of absence - sickness, caring responsibilities, dental appointments and mental health days all count equally toward the score. An employee managing a disability or chronic condition may accumulate a high Bradford score through genuinely unavoidable absences that the organisation has a legal duty to accommodate. Automatic application of Bradford Factor trigger thresholds to disability-related absences is potentially unlawful discrimination. HR best practice is to exclude or separately track absences that have been authorised as disability-related adjustments. Second, the formula does not account for tenure - a new employee who takes five single-day absences in their first year has the same score as a long-serving employee with the same pattern, despite very different context.
When implemented correctly with proper training for managers, the Bradford Factor is a useful standardisation tool. It removes subjective judgement about whose absence pattern is "too much" and provides a consistent, explainable metric that employees can see for themselves. Many modern HR systems display Bradford Factor scores to employees in self-service portals, which creates awareness and accountability without the need for constant manager intervention. Transparency about how the score is calculated and what the trigger thresholds are is essential to employee trust in the system.
Key Points: Bradford Factor
- Formula: S squared x D, where S = number of absence spells and D = total days absent in a rolling 52-week period.
- Logic: Squares the frequency because repeated short absences are more disruptive to operations than a single long absence of equal total duration.
- Trigger thresholds: Common trigger points: 100 for first review, 200 for second review/warning, 400 for final stage - but these are review triggers, not automatic sanctions.
- Disability caveat: Absences related to a disability should be excluded or separately managed to avoid unlawful discrimination.
- Transparency: Showing employees their own Bradford score in a self-service portal creates accountability and reduces need for reactive management.
How Bradford Factor Works in Treegarden
Bradford Factor in Treegarden
Treegarden calculates Bradford Factor scores automatically for every employee as absences are recorded, and updates them in real time. Managers see current scores in their team view and receive automated alerts when a threshold is approaching or crossed. Employees can view their own score in the self-service portal. HR administrators can configure threshold levels, exclude specific absence types from the calculation, and produce Bradford Factor league tables by team for senior management review.
Related HR Glossary Terms
Frequently Asked Questions About Bradford Factor
The Bradford Factor was developed at Bradford University School of Management in the 1980s, originally as a research tool to quantify the disruptive impact of absence patterns. It was subsequently adopted by HR practitioners as a practical management metric. The formula has been in widespread use since the 1990s and is now a standard feature of most HR and absence management software systems.
No. Best practice is to exclude authorised absence types from the Bradford Factor calculation - particularly absence related to a known disability or long-term health condition, maternity leave, bereavement leave and absence for pre-approved medical appointments. Including these in the calculation risks triggering disciplinary action for absences the organisation has a legal duty to accommodate. Most HR systems allow administrators to configure which absence types count toward the Bradford score.
No. A high Bradford Factor score is a trigger for a review conversation, not an automatic disciplinary sanction. The purpose of the review is to understand why the pattern has occurred, check for disability or health conditions requiring adjustments, and agree a management plan. Only if the review reveals that absences are not genuine, or if a supported management plan has failed after a reasonable period, should the process escalate to formal disciplinary action. Skipping straight to a warning when a score crosses a threshold is a procedural error that can lead to unfair dismissal findings.