HR calculator
Absenteeism/Bradford Factor Calculator
Use the Bradford Factor to identify repeated short-term absence patterns. This can support attendance management conversations and workforce planning reviews.
Published under the HR Hub Editorial Team institutional byline and maintained by Michael Walmer, the site operator. No independent professional review is claimed unless a named reviewer is shown.
Bradford Factor Formula
Bradford Factor = (Number of Included Absence Spells²) × Total Included Absence Days
Inputs used in this calculator
- Included Absence Spells: Policy-included absence spells in the defined review period.
- Included Absence Days: Policy-included absence days in the same defined review period.
How to use the result
- Enter the number of separate absence spells.
- Enter the total days absent in the review period.
- Use the Bradford score as one input to attendance review, not as a standalone disciplinary trigger.
Method, scope, and sources
Employer-policy attendance-management convention: Bradford Factor = S² × D, where S is policy-included absence spells and D is total policy-included absence days in the same defined review period. More spells necessarily score higher when days are fixed.
The Bradford Factor is not a universal government statistical standard. The review period, spell-linkage rule, included/excluded categories, scheduled-day basis, part-time treatment, and thresholds belong to the organization’s documented policy. A score is a frequency-weighted attendance-pattern signal, not an absence rate, performance measure, proof of misconduct, or disciplinary determination. Acas guidance is Great Britain-specific.
Method status: Partially supported.
Worked example
Hypothetical only: a written 12-month attendance policy counts three separate sickness-absence spells and seven included scheduled workdays after its exclusions. B = 3² × 7 = 63. The result does not establish risk, misconduct, or an action; the organization must apply its own contextual review process.
Sources
- South Oxfordshire and Vale of White Horse District Councils — Sickness Absence Policy: Directly states the formula as number of times absent × number of times absent × total days absent, and illustrates local choices for rolling period, linkage, part-time treatment, and threshold.
- Acas — Absence trigger points: Says there are no legal rules on when/how absence should be reviewed; the employer should set out its own system and use review points to start a review, not automatically discipline.
- Acas — Disability-related absence – Supporting disabled people at work: Supports Great Britain-specific individual consideration for disability-related absence, including adjustments to counting or trigger points where applicable.
Questions about this calculation
Why does the Bradford Factor emphasize short absences?
The squared spell count makes repeated short absences produce a higher score than a single long absence of the same total duration.
Should the Bradford Factor be used alone?
No. Attendance conversations should always consider context, disability accommodations, and policy fairness.
Read the companion guide
Bradford Factor Calculator Guide: How to Use Short-Term Absence Signals Carefully
Read the HR Hub Editorial Policy or submit a correction or calculator question.