How Many Employees Does One 24/7 Post Need in the United Kingdom?
Holding one position every hour of 2026 in the United Kingdom takes 8,766 staffed hours. One full-time employee is genuinely available for about 1,692 of them, so the post needs 5.18 employees, which is 6 whole people.
One ring per person, one year each
Each ring is one employee's year, broken wherever they are on holiday, on leave, or off sick. No single ring closes, which is the whole problem: one person cannot hold a post that never stops.
Stack 6 of them and the picture closes. Trace any line out from the center and it crosses at least one solid arc, so every hour of 2026 has somebody on it. That is the relief factor, drawn rather than asserted.
Where the number comes from
- 1
Staffing one position 168 hours a week comes to 8,766 hours across the year.
- 2
The United Kingdom has 261 weekdays in the year, the starting point for one employee.
- 3
Take out 28 days of statutory paid leave, 4.4 days of average sickness absence, and 3 days of training: 35.4 days lost. The 5 weekday public holidays are not deducted separately, because in the United Kingdom they sit inside that leave entitlement rather than on top of it.
- 4
That leaves 225.6 working days per employee, and at a 37.5-hour week that is 7.5 hours a day, so 1,692 available hours a year.
- 5
8,766 coverage hours divided by 1,692 available hours is a relief factor of 5.18, so the post needs 6 people.
| Weekdays in the year | 261 |
| Statutory paid annual leave | −28 |
| Average sickness absence | −4.4 |
| Training and onboarding (assumed) | −3 |
| Working days available | 225.6 |
| At 7.5 hours a day | 1,692 hours |
The 28-day entitlement in the United Kingdom is a total that public holidays sit inside, not an amount they sit on top of. Deducting the 5 weekday holidays as well would charge the same days twice, so they are not deducted here.
The training allowance of 3 days is a planning assumption rather than a sourced statistic, and it is deliberately low. Every other figure on this page carries a source. If your operation runs heavy certification cycles, raise it and the relief factor rises with it.
What the usual rule of thumb gets wrong here
The common shortcut is to divide coverage hours by contracted hours and add a quarter for absence. In the United Kingdom that gives 5.6 against a derived answer of 5.18, so the shortcut is high by 8 percent. A flat buffer travels badly because the things it stands in for, statutory leave and the length of the contracted week, are set nationally.
Nobody ever away. Not a real answer.
The usual shortcut, over by 8%.
From the United Kingdom's own leave, hours, and absence.
Other coverage shapes
The same availability figure answers any coverage window. Only the hours the post must be staffed change.
| Coverage | Hours a week | Relief factor | People |
|---|---|---|---|
| Round the clock, every day | 168 | 5.18 | 6 |
| Round the clock, weekdays only | 120 | 3.7 | 4 |
| Two shifts, every day | 112 | 3.45 | 4 |
| Extended day, weekdays only | 60 | 1.85 | 2 |
If your contract is more generous
28 days is the statutory floor in the United Kingdom, and most employers sit above it. Every extra week of leave is another week the post has to be covered by somebody else.
| Annual leave | Relief factor | People per post |
|---|---|---|
| 28 daysstatutory floor | 5.18 | 6 |
| 30 days | 5.23 | 6 |
| 33 days | 5.3 | 6 |
The inputs, and what they do not say
How the leave figure is defined
The law states weeks, not days: 4 weeks (WTR reg 13) plus 1.6 weeks (reg 13A) equals 5.6 weeks, capped at 28 days. On a 5-day week that is 5 x 5.6 = 28 working days. UK law creates no separate statutory right to public holidays, so the 28 days is a total and does not sit on top of bank holidays.
Why the contracted week is not the legal maximum
This page divides by a 37.5-hour week, the typical full-time contract in the United Kingdom, not by the 48-hour statutory figure. That larger number is a legal ceiling on how much someone may be asked to work, not a description of what a full-time employee is contracted for, and using it as capacity would understate the headcount a post needs.
The holiday count is a floor
Most public holidays in the United Kingdom are set regionally rather than nationally, so this page counts only the 5 days observed across the whole country. A specific region will observe more, which pushes the relief factor up. The public holiday calendar for the United Kingdom lists the regional days.
What these figures cannot be used for
Not a ranking. The sickness figure here comes from a national statistical source, while other countries in this library use the OECD labour force survey. Those systems define absence differently, and self-reported survey figures undercount short spells that administrative records capture. Each number is the best available answer for planning inside its own country, and the gap between any two of them is partly a gap between statistical methods rather than between workforces.
A relief factor also says nothing about whether a roster is legal or humane. It sets how many people the post needs across a year; it does not check rest periods between shifts, consecutive nights, or weekend distribution. Those constraints decide whether the pattern you build on top of this headcount is one anybody can actually work.
Research notes on United Kingdom
Leave, the UK trap: 28 days is the statutory floor and bank holidays may be counted inside it. GOV.UK is explicit that an employer can choose to include bank holidays as part of a worker's statutory annual leave. The common UK contract is 20 days plus the 8 England and Wales bank holidays, which exactly meets the 28-day minimum. So if this calculator adds public holidays on top of statutoryAnnualLeaveDays for other countries, do not do it for the UK: 28 + 8 would overstate real time off by 8 days. Use 28 as the all-in figure, or 20 if the engine adds public holidays separately. The 28-day cap is absolute, so someone working 6 days a week still gets 28, not 33.6. Since April 2024, irregular-hours and part-year workers accrue at 12.07 percent of hours worked rather than a fixed day count. Northern Ireland runs under the mirror Working Time Regulations (NI) 1998 with the same 5.6 weeks and 28-day cap, but has 10 bank holidays against 8 in England and Wales and 9 in Scotland, which shifts the effective split.
Weekly hours: 48 is a health-and-safety ceiling on average working time over a rolling 17-week reference period, not a normal or standard week. The UK has no statutory standard working week at all, and unlike most of the EU it still permits an individual written opt-out from the 48-hour limit, so 48 should never be used as a planning baseline. Night workers are separately limited to an average 8 hours per 24, and under-18s to 40 hours per week with no averaging.
Collective week: the UK has no national collective agreement setting hours and collective bargaining coverage is low, so 37.5 is a measured typical rather than a negotiated norm. It is the ONS ASHE median of basic (contracted, overtime-excluded) paid hours for full-time employees in April 2025; the ASHE mean is 37.8. The LFS measure of hours actually worked by full-time workers averaged 36.5 in 2025, lower because it nets out leave and absence, so 36.5 and 37.5 are consistent rather than conflicting. A 40-hour contract is common in shift and manual sectors, so 37.5 is a median, not a ceiling.
Sickness: 4.4 days per worker in 2025 is the ONS figure across all people in employment aged 16 and over, which includes part-timers. Full-time-only absence is higher, so scale up if the calculator models full-time staff. The overall rate was 2.0 percent of working hours lost. ONS classes this series as official statistics in development and flags increased volatility in 2023 to 2024 from Labour Force Survey methodology changes, so treat year-on-year moves of a tenth of a day as noise. It is self-reported survey data, which tends to understate short one-day absences relative to employer payroll records.
Sources
Every figure above except the training allowance was checked against one of these.
Statutory maximum weekly working time: 48 hours averaged over 17 weeks, with individual opt-out
Working Time Regulations 1998 reg 4: working time shall not exceed an average of 48 hours for each seven days, over a 17-week reference period
Median basic (contracted) paid hours for full-time employees: 37.5 per week, mean 37.8. ASHE 2025 provisional, Table 1.10a, Full-Time sheet
Office for National Statistics, Annual Survey of Hours and Earnings2025
Average actual weekly hours of work for full-time workers (series YBUY): 36.5 hours, 2025 annual average
Office for National Statistics, Labour Market Statistics2025
Statutory paid holiday: 5.6 weeks, minimum 28 days for a 5-day week, limited to 28 days; an employer can choose to include bank holidays as part of statutory annual leave
Working Time Regulations 1998 reg 13A: additional 1.6 weeks leave from 1 April 2009, aggregate entitlement subject to a maximum of 28 days
Corroboration that bank holidays might be included in the 5.6 weeks and that workers should check their contract
8 bank holidays in England and Wales, 9 in Scotland, 10 in Northern Ireland
Average 4.4 days lost per worker, sickness absence rate 2.0 percent of working hours, 148.8 million working days lost
Common questions
- How many people does one 24/7 position need in the United Kingdom?
- 6 people. One position staffed every hour of the year is 8,766 hours, and one full-time employee in the United Kingdom is actually available for about 1,692 of them once 35.4 days of holidays, leave, sickness and training come out. That is a relief factor of 5.18, which rounds up to 6 whole people.
- What is a relief factor?
- The number of employees needed to keep one position filled continuously, once the days nobody works are taken out. It is coverage hours divided by the hours one employee is genuinely available. In the United Kingdom that is 8,766 divided by 1,692, or 5.18. A factor below the headcount you actually employ means the post runs on overtime.
- Why is a flat 25 percent absence buffer not enough for the United Kingdom?
- Because it overshoots here. A raw hours calculation gives 4.48 employees, and adding a flat quarter takes that to 5.6, against a derived answer of 5.18. That is 8 percent too high, because the rule of thumb assumes more leave and sickness than the United Kingdom actually loses.
- Does the statutory leave minimum reflect what employers actually give in the United Kingdom?
- It is a floor, not a norm. This page computes on the statutory minimum of 28 working days because that is the figure the law fixes and a source can be attached to. Most employers sit above it, and the sensitivity table on this page shows what the relief factor becomes at more generous entitlements, so a planner can find their own contract rather than taking the floor as the answer.
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