The Bradford Factor Calculator works out how disruptive an employee's absence pattern has been, using the formula B = S² × D, where S is the number of separate absence occasions and D is the total number of days absent over a rolling 52-week period. Because the spell count is squared, several short unpredictable absences score far higher than one long continuous absence covering the same days, reflecting how much harder frequent gaps are to plan around. You enter the number of separate absence occasions and total days absent, plus your own trigger points for medium, high, serious and critical concern if they differ from the common defaults of 50, 200, 400 and 1,000. The calculator returns the Bradford Factor score, a breakdown showing S squared and the multiplication behind it, and a comparison against what the score would be if the same days occurred as one continuous spell or as separate one-day absences. It also flags which concern band the score falls into and gives a written summary of the suggested response. Use the result as a starting point for a conversation about the reasons behind the absences, not as an automatic trigger for discipline. The threshold bands shown are common industry guidelines rather than a legal requirement, so set your own policy and investigate individual circumstances before taking formal action.
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Reviewed June 2026
Standard Bradford Factor formula. Threshold bands are illustrative guidelines; set your own organisational policy.
1. Absence Data (rolling 52 weeks)
2. Your Organisation's Trigger Points
Bradford Factor Result
Absence Spells (S)
3
Separate occasions
Bradford Factor Score
90
B = S² × D
Total Days Absent (D)
10
Over 52 weeks
Bradford Factor Band
Low concern0 to 49No formal action; monitor only
Medium concern50 to 199Informal discussion with manager
High concern200 to 399Formal review or written warning
Serious concern400 to 999Final written warning
Critical1,000+Disciplinary proceedings may be considered
Calculation Breakdown
Separate spells (S)3
S squared (S²)9
Total days absent (D)10
Bradford Factor (S² × D)90
Scenario Comparison
1 spell, same total days-
Your result (S spells)-
Each spell = 1 day each-
Multiplier vs 1 spell-
Summary:
What Is the Bradford Factor?
The Bradford Factor is a human resources tool used to measure the impact of employee absences. It was developed at the University of Bradford's management centre and is based on the observation that frequent short-term absences are more disruptive to an organisation than a single long absence of the same total length. A manager can plan for an employee who is off for three weeks with a known illness; the same three weeks spread across six unpredictable one-day absences is much harder to cover.
The formula is: B = S² × D
Where B is the Bradford Factor score, S is the number of separate absence occasions in a 52-week rolling period, and D is the total number of days absent in the same period. Because S is squared, adding more spells increases the score exponentially even if the total days stay the same.
Worked Example
Using the default values: an employee had 3 separate absence spells totalling 10 days in the past year.
S = 3, so S² = 3 × 3 = 9
D = 10
Bradford Factor = 9 × 10 = 90
A score of 90 falls in the medium concern band (50 to 199), suggesting an informal discussion with the employee's manager is appropriate. By contrast, if those same 10 days were a single continuous absence (S = 1), the score would be 1 × 10 = 10, which is low concern. This illustrates how the formula penalises frequent short absences.
Common Bradford Factor Thresholds
Score Range
Typical Band
Suggested Response
0 to 49
Low concern
No formal action; routine monitoring
50 to 199
Medium concern
Informal discussion with line manager
200 to 399
High concern
Formal review or first written warning
400 to 999
Serious concern
Final written warning
1,000 and above
Critical
Disciplinary proceedings may be considered
These bands are illustrative and organisations should set their own thresholds in an absence management policy. Thresholds may differ by role (for example, a lower threshold for roles requiring physical presence) or industry.
Important Limitations
The Bradford Factor is a diagnostic aid, not a disciplinary shortcut. Before taking any action based on a high score, managers should investigate the reasons for each absence. Absences related to a disability, chronic condition, pregnancy, or other protected characteristic must be handled carefully. In New Zealand, the Employment Relations Act 2000 and the Human Rights Act 1993 require employers to consider reasonable accommodations and to follow a fair process. Dismissing an employee solely on the basis of a Bradford Factor score without proper investigation and process is likely to be challenged as an unjustified dismissal.
Best practice is to use the score as a trigger for a supportive, non-adversarial return-to-work conversation rather than immediate disciplinary action.
Method note: The Bradford Factor formula B = S² × D is the standard published formulation widely used in HR practice. Threshold bands are based on commonly cited industry guidelines and are not set by any NZ legislation. Organisations should define their own trigger points in a written absence management policy.
This calculator is for informational purposes only and does not constitute employment advice. Before taking action based on absence scores, employers should follow a fair process, consider the reasons for absence, and seek advice from an employment relations specialist where appropriate.
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