How many employees do you need to cover 16 hours a day, 7 days a week with 8-hour shifts?
Two shifts a day, seven days a week comes to 112 coverage hours, which works out to 2.8 FTE, a minimum of 3 people, and a realistic roster of 4.
The short answer
Covering 16 hours a day, 7 days a week with one person on duty means staffing 112 hours a week: a minimum of 3 employees at 37.3 hours each, and realistically 4 once holidays, sickness, and training are priced in.
- Coverage window
- 16 hours a day, 7 days a week
- Hours to staff / week
- 112
- Shift length
- 8h
- Shifts to fill / week
- 14
- Bare minimum
- 3 people
- With absence buffer
- 4 people
Why the math lands there
The arithmetic starts with the coverage window. Sixteen hours a day times seven days is 112 coverage hours per week. With one person on duty and 8-hour shifts, that is 14 shifts a week, an early and a late every day. Spread across 40-hour contracts, 112 hours comes to 2.8 full-time equivalents. You cannot hire 2.8 people, so the minimum roster is 3, each averaging 37.3 hours per week.
Three people at 37.3 hours looks comfortable on paper. Each person is slightly under full time, nobody is near the EU Working Time Directive cap of a 48-hour average week. The rule that does bite is the EU's 11 hours of daily rest: a late ending at 22:00 followed by an early at 06:00 leaves only 8 hours, so the rotation must never put an early straight after a late. The catch is not hours, it is days. Fourteen slots spread across 7 days means all 3 people work weekends on a regular rotation, and there is no version of this roster where someone gets every Saturday and Sunday off without the other two absorbing the difference.
Running 2 people is not an option: 112 hours split two ways is 56 hours each, over any reasonable limit and over the 48-hour EU average cap. A fourth person drops everyone to 28 hours, which sounds like overstaffing until you price in vacation, sick leave, and the weekend rotation. With 4 people you can build a rotation where each person gets roughly every other weekend off. With 3, weekends off come around less often and every absence lands on the remaining two.
- 116 hours a day times 7 days a week = 112 coverage hours to staff every week.
- 2112 hours divided into 8-hour shifts = 14 shifts to fill every week.
- 3112 hours divided by a 40-hour workweek = 2.8 full-time equivalents, so 3 employees minimum.
- 4Nobody works every scheduled week. With a typical 20 to 25 percent allowance for leave, sickness, and training, plan for 4 people to keep the roster from running on overtime.
Headcount options, side by side
The same 112 weekly coverage hours spread over different team sizes. Average weekly hours per person is the number that decides whether a roster is sustainable, legal, and affordable.
| People | Hours / person / week | Shifts / person / week | Verdict |
|---|---|---|---|
| 1 | 112 | 14 | Not viable |
| 2 | 56 | 7 | Over legal limits in most countries |
| 3this page | 37.3 | 4.7 | Standard workload |
| 4 | 28 | 3.5 | Slack for absence |
| 5 | 22.4 | 2.8 | Slack for absence |
| 6 | 18.7 | 2.3 | Slack for absence |
The absence buffer above assumes 20 to 25 percent of paid time goes to leave, sickness, and training. Your own rate decides the real number, which you can work out with our shrinkage calculator.
What the arithmetic does not tell you
The number the arithmetic hides is weekend frequency. With 3 people covering 14 weekly slots, 4 of those slots fall on Saturday and Sunday, and someone has to take them every single week. A fair rotation gives each person a free weekend roughly one week in three at best, and that is before anyone requests a specific Saturday off. If your team expects alternating weekends, 3 people cannot deliver it and 4 is your real minimum, not a luxury.
The 06:00-22:00 window is a choice, not a given. If your demand actually runs 07:00 to 21:00, you are paying for 2 low-value hours a day, 14 hours a week, which is a third of one person's schedule. Also decide what happens at 14:00 when early hands over to late. If the handover needs 15 minutes of overlap, that is not free: 14 overlaps a week add about 3.5 hours you either build into the shifts or lose from coverage. Back-to-back shifts with zero overlap work only if the role needs no briefing.
At 37.3 average hours, the schedule cannot be a clean repeating week for all 3 people. Fourteen shifts across 3 people means a 5-5-4 split that rotates, so each person's week looks different from the last. That is manageable, but it means you are publishing a rotating schedule, not pinning a fixed one, and every swap request ripples across the weekend rotation you worked to keep fair.
Once the headcount is settled, the daily work is keeping the roster fair and covered as people swap, call in sick, and take leave. That is the part Soon automates, from constraint-aware auto-scheduling to leave management.
Frequently asked questions
- How many employees do you need for 16/7 coverage with 8-hour shifts?
- Covering 16 hours a day, 7 days a week with one person on duty requires 112 coverage hours per week, which is 2.8 FTE at a 40-hour target. The minimum roster is 3 people averaging 37.3 hours each. A realistic roster is 4 people at 28 hours each, which makes weekend rotation and absence cover workable.
- Can 2 people cover a 16-hour, 7-day operation?
- No. Splitting 112 weekly coverage hours between 2 people means 56 hours each, every week, with no days off structure that holds up. That exceeds the EU Working Time Directive cap of a 48-hour average week and leaves zero cover for sickness or vacation. Three people is the floor for this configuration.
- How do weekends work with 3 people on a 16/7 two-shift schedule?
- There are 14 shifts a week and 4 of them fall on Saturday and Sunday, so with 3 people everyone works weekends on rotation. The best a fair 3-person rotation delivers is a free weekend roughly every third week. If staff expect every other weekend off, you need 4 people, at which point each averages 28 hours per week.
- What is the best shift structure for 06:00 to 22:00 coverage?
- The standard split is an early shift from 06:00 to 14:00 and a late shift from 14:00 to 22:00, giving 14 shifts a week. The main design decision is the 14:00 handover: if the role needs a briefing, build a short paid overlap into the shift times rather than assuming a zero-minute handover. One constraint to respect: the EU requires 11 hours of daily rest between shifts, and a 22:00 close into a 06:00 open leaves only 8, so never roster an early directly after a late.
- Is 3 people at 37.3 hours each a full-time schedule?
- It averages 37.3 hours, slightly under a standard 40-hour week, so most operations treat it as full time. The trade-off is that 14 shifts do not divide evenly by 3, so the roster runs a rotating 5-5-4 shift split rather than an identical week for each person. Every person works weekends regularly, which matters more to retention than the hours number.
Adjacent staffing questions
How many people do you need to cover 16 hours a day, Monday to Friday, with 8-hour shifts?
Two 8-hour shifts a day, five days a week: 80 coverage hours, exactly 2.0 FTE, and no room for a single sick day.
80 hours/week · 8h shifts
See the math →How many people do you need to cover 12 hours a day, 7 days a week with 12-hour shifts?
One 12-hour shift per day, seven days a week: 84 coverage hours, 2.1 FTE, and a straight choice between 2 people at 42 hours or 3 at 28.
84 hours/week · 12h shifts
See the math →How many employees do you need to cover 24/7 with 8-hour shifts?
168 hours a week divided into 21 eight-hour shifts is 4.2 FTE, and that fraction is the whole problem.
168 hours/week · 8h shifts
See the math →Your next schedule could take 2 minutes.
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