Bradford factor calculator
Work out an employee’s Bradford factor from their spells and days of absence, or straight from the dates they were off.
Absences
Count sickness absence over a rolling 52 weeks, the usual period for the Bradford factor.
Separate periods off. Three days off in a row is one spell.
Working days missed across all the spells.
Bradford factor
54
3² × 6 = 9 × 6 = 54
- Spells
- 3
- Days absent
- 6
Example trigger points
Informal conversation
- No concern0–50
- Informal conversation51–124
- First formal review125–399
- Second formal review400–649
- Final review650+
There is no legal scale. Employers set their own trigger points in their absence policy, and should leave out disability and pregnancy-related absence.
What is the Bradford factor?
The Bradford factor is a score for sickness absence that gives more weight to frequent, short absences than to fewer long ones. HR teams use it to spot absence patterns that may need a conversation, such as regular single days off.
The Bradford factor formula
B = S² × D
- S is the number of separate spells of absence. Three days off in a row is one spell.
- D is the total number of days absent across all the spells.
Both are usually counted over a rolling 52 weeks. An employee off for 2 days in March, 1 day in June and 3 days in September has 3 spells and 6 days: 3² × 6 = 54.
Why spells matter more than days
Because spells are squared, the same days off can score very differently. Here are 10 days of absence taken in different ways:
| 10 days taken as | Calculation | Score | Example trigger point |
|---|---|---|---|
| 1 spell | 1² × 10 | 10 | No concern |
| 2 spells | 2² × 10 | 40 | No concern |
| 5 spells | 5² × 10 | 250 | First formal review |
| 10 spells | 10² × 10 | 1,000 | Final review |
Bradford factor trigger points
Employers that use the Bradford factor set trigger points: scores at which an absence review starts. There is no legal or standard scale, and Acas notes there are no legal rules on how or when absence should be reviewed. This is one commonly used example:
| Score | Example action |
|---|---|
| 0–50 | No concern. Below most review points. |
| 51–124 | Informal conversation. A first check-in on how the employee is doing. |
| 125–399 | First formal review. A formal absence meeting, with support agreed. |
| 400–649 | Second formal review. A follow-up review of the support and targets. |
| 650+ | Final review. The last stage of the absence procedure. |
Write the trigger points into your absence policy so everyone knows how absence is reviewed, and apply them consistently.
Using the Bradford factor fairly
The Bradford factor is a blunt tool. It counts absences without knowing why they happened, so using it mechanically can treat people unfairly, and in some cases unlawfully.
Disability-related absence
Many long-term conditions lead to frequent short absences, which is exactly what the Bradford factor punishes most. Under the Equality Act 2010, employers must make reasonable adjustments for disabled employees, and Acas suggests this can include not counting some or all disability-related absence towards trigger points, or raising the trigger points for that employee.
Pregnancy-related sickness
Treating an employee unfavourably because of pregnancy-related illness during the protected period is discrimination under section 18 of the Equality Act 2010. Leave pregnancy-related sickness out of the score. Acas recommends recording pregnancy and disability-related absence separately, so it is easy to leave out.
A prompt for a conversation
Treat a high score as a reason to talk, not as an automatic warning. A return-to-work chat or absence review can uncover a health problem, caring responsibilities or issues at work that support or adjustments could help with.
This calculator gives a score, not advice. Before acting on absence, check your own policy and get advice from Acas or an employment adviser.
How this calculator counts
- With dates, Monday to Friday count as working days, and only the 52 weeks up to the chosen date are counted.
- Absences that overlap, or are separated only by a weekend, count as one spell, since the employee did not return to work in between.
- Public holidays and part-time patterns are not taken into account. Use the totals mode to enter your own counts.
Frequently asked questions
How do you calculate the Bradford factor?
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Square the number of separate absence spells, then multiply by the total days absent: B = S² × D. Someone with 3 spells and 6 days off in the last 52 weeks scores 3² × 6 = 54.
What is a good Bradford factor score?
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Lower is better, and 0 means no absence. There is no official scale, but many employers treat scores under about 50 as no cause for concern. What counts as high depends on the trigger points in your own absence policy.
Why does the Bradford factor count spells more than days?
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Frequent short absences are usually more disruptive to plan around than one long one, so the formula squares the number of spells. Ten single days off score 1,000, while one ten-day absence scores just 10.
What period does the Bradford factor cover?
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Most employers use a rolling 52 weeks, counting back from today. Older absences drop out of the score as time passes.
Is the Bradford factor legal?
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Yes, it is a common management tool, but it is not set by law. Using it mechanically can lead to discrimination: Acas suggests not counting disability-related absence towards trigger points, or raising them, as a reasonable adjustment, and pregnancy-related sickness should not count against an employee.
Why is it called the Bradford factor?
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The name is usually linked to research at the University of Bradford's School of Management in the 1980s, but the university has not confirmed this and the exact origin is unclear.