Bradford Factor Calculator (Free) + Complete UK Guide 2026

What is the Bradford Factor?

The Bradford Factor is a formula used by HR teams to measure the impact of employee absences. It was developed at the Bradford University School of Management in the 1980s and has since become standard practice in UK workplaces.

The key insight behind the Bradford Factor is that frequent short absences are typically more disruptive to a business than occasional longer absences. Someone who takes ten single days off causes more operational disruption than someone who takes one ten-day block, even though the total days are the same.

The Bradford Factor Formula

The formula is simple:

Where:

• B = Bradford Factor score
• S = Number of separate absence spells (instances) in a set period
• D = Total number of days absent in that period

The "S × S" (S squared) is what makes the formula sensitive to frequency. Multiple short absences dramatically increase the score compared to fewer, longer absences.

Bradford Factor Examples

Let's see how this works in practice over a 12-month rolling period:

Same total days off (10), but the Bradford Factor scores are dramatically different. This reflects the operational reality that covering for frequent unexpected absences is more disruptive than planning around one known absence.

Bradford Factor Score Ranges: What's Concerning?

There's no universal standard for "good" or "bad" Bradford Factor scores—every organisation sets their own thresholds. However, these ranges are commonly used as starting points:

Important: These are guidelines, not rules. Scores must always be considered alongside context—see the limitations section below.

UK Benchmarks

According to CIPD data, the average UK employee takes approximately 7.8 days of sickness absence per year. For an employee with average absence distributed across 3 spells, this would give a Bradford Factor of approximately:

So a score under 70 is roughly "average" for the UK workforce.

How to Calculate Bradford Factor for Your Team

Step 1: Define Your Rolling Period

Most organisations use a 12-month rolling period. This means you look back 12 months from today, not a fixed calendar year. Rolling periods prevent unfair comparisons where someone's January absence lingers on their record until the following January.

Step 2: Count Absence Spells

An absence spell is a continuous period of absence. If someone is off Monday, Tuesday, and Wednesday, that's one spell of 3 days. If they return Thursday and are then off again Friday, that's two spells.

Be consistent about what counts:

• Do you count half-days as full spells?
• How do you handle absences that span weekends?
• What about pre-planned medical appointments?

Step 3: Count Total Days

Add up all the absent days within your rolling period. Again, be consistent about half-days and what you include.

Step 4: Apply the Formula

S × S × D = Bradford Factor

Limitations of the Bradford Factor

The Bradford Factor is a useful indicator but it has significant limitations that every HR professional should understand.

It Doesn't Account for Disability

Employees with disabilities or long-term health conditions may have legitimate reasons for more frequent short absences. Using the Bradford Factor to penalise these employees could constitute disability discrimination under the Equality Act 2010.

What to do: Always review scores in context. Exclude disability-related absences or apply reasonable adjustments to your thresholds.

It Penalises Certain Medical Conditions

Conditions like migraines, IBS, or mental health issues often cause unpredictable short absences rather than extended sick leave. The Bradford Factor's frequency weighting can unfairly penalise employees managing these conditions.

It Can Encourage Presenteeism

When employees know they're being scored on absence frequency, some will come to work when they should stay home. This can spread illness to colleagues and prolong recovery times.

ACAS Guidance

ACAS recommends that the Bradford Factor should be one of several factors considered when managing absence, not the sole measure. They emphasise:

• Individual circumstances must always be considered
• Disability-related absence should be treated separately
• The focus should be on supporting employees, not punishment
• Trigger points should be used to prompt conversations, not automatic sanctions

Tracking Bradford Factor Automatically

Calculating Bradford Factor manually becomes unmanageable as your team grows. You need to:

• Track every absence spell accurately
• Maintain rolling 12-month windows
• Recalculate whenever new absences occur
• Generate reports for HR reviews

OrOut calculates Bradford Factor automatically for your entire team. Every time someone logs an absence through Slack or Teams, their Bradford Factor updates in real-time. You can see individual scores on each employee profile and run reports across departments.

No spreadsheets. No manual calculations. No portal to log into.

Frequently Asked Questions

Summary

The Bradford Factor is a useful tool for identifying patterns in employee absence, but it's not a replacement for good management judgment. Use it to prompt conversations and identify potential issues, not to automatically trigger disciplinary action.

Key points to remember:

• The formula is S × S × D (spells squared times days)
• Frequent short absences score higher than infrequent long absences
• Always consider individual circumstances, especially disability
• Use it as one input among many, not the sole measure
• Track it automatically to avoid spreadsheet chaos