Bradford Factor Calculator

Calculate Bradford Factor score from absence spells and days lost, then review average days per spell, annualized score, and policy-trigger support.

Last updated 26 March 2026

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HR Planning

Bradford Factor calculator guide: short-absence scoring, annualized Bradford score, and trigger-threshold planning

A Bradford Factor calculator is built to highlight how disruptive repeated short absences can be. Instead of looking only at total days lost, it squares the number of separate absence spells and multiplies by the total days absent, which means the score rises much faster when the same time away is split across multiple short episodes.

About this calculator

Reviewed 2026-03-26

Methodology

Squares the number of absence spells and multiplies by total days absent to calculate the Bradford score, then annualizes the score over the review period entered, compares it with an optional trigger score, and optionally normalizes days lost by average employees.

Limitations

Treats absence spells mathematically rather than legally or medically, so it does not separate protected, disability-related, pregnancy-related, or other policy-excluded absences automatically.
Annualized score assumes the current period is representative enough to scale to 12 months, even though attendance patterns can cluster unevenly through the year.
Trigger comparisons are illustrative only because employers use different review periods, thresholds, and exclusions.
This is an attendance-planning aid, not a disciplinary, legal, or employee-relations decision tool.

Disclaimer

Use the result as an attendance-management aid only. Before relying on it for employee-relations decisions, confirm the employer's absence policy and any legal or protected-context requirements that apply.

Sources

GOV.UK - Sickness absence and health in the workplace report — Official UK government report covering sickness-absence management and employer attendance practice.
Acas - Recording and reducing sickness absence — Acas guidance on recording and reducing sickness absence fairly in the workplace.
Acas - Disability-related absence — Acas guidance highlighting why disability-related absence context matters when attendance triggers are used.

See our calculation methodology and editorial standards for how this estimate is produced.

What the Bradford Factor is measuring

The Bradford Factor is an attendance-pattern score, not a total-time-lost measure alone. One longer absence can produce a lower score than the same number of days taken in several shorter absences, because the metric is specifically designed to weight frequency more heavily than duration.

That is why the score often appears in attendance-management policies. It is meant to help employers spot patterns of repeated short absence that may create more operational disruption than one continuous period away from work.

The formula and the trigger view

This calculator uses the common Bradford formula of absence spells squared multiplied by total days absent. It also annualizes the score over the review period entered, compares the result with an optional trigger score, and can normalize days lost by average employees when you want basic per-employee context for the same period.

The trigger support is useful because it converts a policy threshold into something operational. At the current number of spells, you can see how many total days absent would still fit under the trigger, and at the current days lost you can see how many whole spells would still stay below it.

Bradford Factor = Absence spells² x Total days absent

The standard attendance-pattern score used to weight frequency more heavily than duration.

Annualized Bradford score = Bradford Factor x (12 / Review period in months)

A comparison view that scales the current-period score to a 12-month equivalent.

Worked example: four spells and nine days lost

Suppose an employee records 4 absence spells and 9 days lost across a 12-month review period. The Bradford score is 144. Average days per spell are 2.25, and if the policy trigger is 100 the score is already 44 points above that level.

The same example also shows why the trigger support matters. At 4 spells, only 6.25 days could be lost before reaching a score of 100, so the pattern is already beyond that threshold even though the total days absent may not look extreme on their own.

Why Bradford scores need careful use

A Bradford score is a discussion aid, not a disciplinary decision on its own. Disability-related absence, pregnancy-related absence, long-term sickness, and other protected or policy-excluded categories may need to be handled differently from general short-term attendance review.

It is also important not to assume trigger levels are universal. Different employers use different thresholds, different review periods, and different absence exclusions, so the same raw score can have very different consequences depending on the policy framework around it.

Bradford Factor Calculator

Bradford Factor calculator guide: short-absence scoring, annualized Bradford score, and trigger-threshold planning

What the Bradford Factor is measuring

The formula and the trigger view

Worked example: four spells and nine days lost

Why Bradford scores need careful use

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