Bradford Factor calculator

What a Bradford Factor calculator is counting

The Bradford Factor is a way of comparing short, repeated sickness with one longer spell. The sum is the number of separate spells, squared, times the number of sick days: S² × D. Three separate days score higher than one spell of three days, because the spells are squared. It is a management figure. It is not a statutory score, and GOV.UK does not set a number at which you must act.

This Bradford Factor calculator does the arithmetic from the spells and days you type. It does not read a rota, merge a weekend into one spell, or know which bank holidays the workplace was closed. If you already know S and D for the last 52 weeks, type them. If you only have the length of each spell, add the lengths for D and count the spells for S before you start.

A score on its own does not say the absence was unfair, or that a warning is due. Some workplaces use their own bands. Those bands are a local rule, not the law. This page will not suggest a cutoff. Talk to the person before you treat a number as a reason to act. Disability-related absence and pregnancy-related absence raise discrimination questions. GOV.UK sets out those rights. Leaving those spells in a score can be the wrong step even when the multiplication is correct.

Spells and days, including a half day

S is a whole number. Ten single days are ten spells. One illness that runs Monday to Friday is one spell, even though it is five days. D is the sick days across the spells you are counting. One spell of 10 days is 1² × 10 = 10. Ten spells of one day are 10² × 10 = 1,000. Three spells that add up to 7 days are 3² × 7 = 63. The same days, split differently, are a different score. That is the point of the square.

A half day can sit in D. Two spells and half a day are 2² × 0.5 = 2. The page rounds the days to two decimal places, then rounds the score to two decimal places. Zero spells is a score of zero. A spell count that is not a whole number is rejected, because half a spell is not a thing this sum understands.

What counts as one spell is the part this form will not decide for you. In Shiftbrook, approved sickness over a rolling 52 weeks is grouped by the working pattern. Consecutive working days are one spell. A weekend, or a bank holiday the organisation is closed, does not start a new spell. A working day that is not sick does. A one-day absence uses the hours divided by the person’s day length, capped at one day, so a half day stays a half day. A longer absence counts each working day in the range as one day. Pending, declined and cancelled sickness is left out. The window is 52 weeks ending on the organisation’s today, 364 days inclusive. Days outside it are dropped. A spell that crosses the start still counts once, and only the days inside the window add to D.

What Shiftbrook shows, and what it refuses to do

The score stays off until an owner or admin switches it on under Settings, then Privacy. Nothing is emailed, and there is no warning level. Owners, admins, people with HR access and that person’s line manager can see the score. The person cannot. Other staff cannot. A client user cannot. Reports can show a Bradford column on Absence only after the score is on, and that column is the rolling 52 weeks, not the dates on the report.

An owner, admin, someone with HR access, or the line manager can leave a spell out as disability-related, pregnancy-related, or another reason. The absence stays on the record. It is marked as not counted, and it drops out of S and D. Putting it back includes it again. The product does not read a fit note, it does not calculate Statutory Sick Pay, and it does not tell you that a pattern is unfair.

Use the SSP calculator when the question is the 2026/27 weekly rate. Use the holiday entitlement calculator when the question is 5.6 weeks or 12.07% of hours. Use this page when the question is the Bradford arithmetic, and then talk to the person.

One spell of 10 days

1. Spells: 1. Days: 10.
2. 1 squared is 1. 1 × 10 = 10.
3. One longer spell scores less than the same days split into many spells.

Ten separate days

1. Spells: 10. Days: 10.
2. 10 squared is 100. 100 × 10 = 1,000.
3. The page does not decide whether those ten days were separate spells. You do.

Three spells adding up to 7 days

1. Spells: 3. Days: 7. That could be two single days and one spell of five.
2. 3 squared is 9. 9 × 7 = 63.
3. A half day is allowed in the days field. Two spells and 0.5 days score 2.