Bradford Factor Calculator

What is the Bradford Factor?

The Bradford Factor is a score for sickness absence that counts how often someone is off more heavily than how long. It's S × S × D: the number of separate spells of absence, squared, times the total days absent. It's also called the Bradford score, Bradford index or Bradford formula.

Because the spells are squared, frequent short absences score far higher than one long one. Over the same 6 days:

• 1 spell of 6 days scores 1 × 1 × 6 = 6.
• 3 spells of 2 days score 3 × 3 × 6 = 54.
• 6 spells of 1 day score 6 × 6 × 6 = 216.

Employers use it to see when a pattern of short absences needs a conversation. It doesn't say why someone was off, so it's a reason to talk, not a verdict.

How do you calculate a Bradford Factor score?

1. Choose the period. Use the one your absence policy sets, such as the last 52 weeks.
2. Count the spells: the separate absences in that period.
3. Count the days: the total days absent across those spells.
4. Multiply the spells by themselves, then by the days.

Someone off 3 times in the last 52 weeks, for 1 day, 2 days and 3 days, has 3 spells and 6 days. Their score is 3 × 3 × 6 = 54.

What counts as a spell?

A spell is one continuous absence, however long it lasts. 3 days off in a row is 1 spell. 3 separate days off is 3 spells. A half day off is a spell too, of 0.5 days.

Days someone wasn't due to work, like a weekend, don't add to the days and don't break a spell. Someone off sick on Friday and still off on Monday is usually counted as 1 spell of 2 days, because they weren't back at work in between. Your absence policy should say how it counts them.

What counts as absence?

Unplanned absence, which is usually sickness. Holiday and other leave booked in advance aren't spells. Some absence shouldn't be counted, or needs a different approach: see which.

Bradford Factor scores for common absence patterns

Find the spells on the left and the total days absent along the top. Scores rise much faster with more spells than with more days.

What is a good or bad Bradford Factor score?

There's no legal or standard score that's good or bad. In the UK, there are no legal rules about how or when absence should be reviewed, so each employer sets its own review points (sometimes called trigger points) in its absence policy. A lower score means fewer or shorter absences, and 0 means none.

Reaching a review point should start an absence review, not disciplinary action. ACAS says employers should not use review points to trigger disciplinary action automatically. If people see them as a punishment, it could cause more absence, with people coming back to work before they're well. In the review, the employer talks with the person to:

• check on their wellbeing
• discuss the reasons for their absence
• see how the employer can support them

If an employer uses the Bradford Factor, the absence policy should say what the review points are, how someone is told they've reached one, and that reaching one starts a review. See ACAS's guidance on absence trigger points.

What absence shouldn't count towards a Bradford Factor score?

Some absence needs to be left out, or looked at differently, so the score doesn't put someone at a disadvantage the law protects them from. Leave those days and spells out before you enter them.

Disability-related absence

Someone who's disabled may need time off for treatment, appointments or recovery, and reach review points sooner because of it. In Great Britain, the Equality Act 2010 says employers must make reasonable adjustments for disabled people (in Northern Ireland, it's the Disability Discrimination Act 1995). For absence, ACAS gives these as examples:

• not counting some or all disability-related sickness absence towards review points
• raising the number of absences that triggers a review
• recording disability-related absence separately from other sickness absence

What's reasonable depends on the person and the circumstances. Read ACAS's guidance on disability-related absence.

Pregnancy-related sickness

Employers should record pregnancy-related sickness separately from other sickness absence, and not count it towards review points. Read ACAS's guidance on pregnancy-related sickness.

Other absence to look at in a review

ACAS also says to consider whether the absence was caused by work, such as an accident or work-related stress, and whether the person was entitled to time off for dependants because of an emergency with someone who depends on them.