Absence Rate Calculator
Absence rate for a team, plus the Bradford Factor — with a warning about how it is often misused.
Absence rate is days lost divided by days available.
How the absence rate calculator works
Absence rate is days lost divided by days available. It is simple and it hides the pattern completely: ten people off for one day each and one person off for ten days give an identical rate and mean entirely different things.
The Bradford Factor addresses that by weighting frequency heavily: S² × D, where S is the number of separate absence spells and D is total days. Ten one-day absences score 1,000; one ten-day absence scores 10. The reasoning is that short, frequent, unplanned absences disrupt a team more than one planned longer one.
It is worth being direct about the criticism. Applied mechanically as a trigger, the Bradford Factor penalises chronic and disability-related conditions and pressures people into working while unwell. It is a prompt for a conversation, not a disciplinary threshold, and several employers have abandoned it for exactly that reason.
Formula: absence rate = days lost / days available; Bradford = spells² × days
Worked examples
| Inputs | Absence rate | Note |
|---|---|---|
| 380 days lost across 45 people | 3.378% | 3.38% absence rate |
| Frequent short absences | 3.378% | Bradford 1,000 |
| One long absence | 3.378% | Bradford 10 |
FAQFrequently asked questions
How do I calculate absence rate?
Days lost divided by days available — headcount times working days in the period.
What is the Bradford Factor?
Spells squared times total days. It weights frequent short absences far more heavily than one long one.
Why does it square the number of spells?
On the reasoning that unplanned short absences disrupt a team more than a single planned longer one.
Is the Bradford Factor fair?
Used mechanically as a trigger, it penalises chronic and disability-related conditions and encourages people to work while unwell. Several employers have dropped it for that reason.
What is a normal absence rate?
Commonly 2 to 4% in office environments, higher in shift and frontline work. Compare against your own history.
Where these figures come from
- CIPD — Employee turnover and retention factsheet — the turnover and stability index definitions used here
- Acas — the UK workplace advice service
Last checked: September 2026. These are standard management definitions; where practice varies, the page says which convention it uses.