How many employees to cover 24/7, worked out
A week has 168 hours. To keep 1 person on shift every hour, 4 people on a 4-crew rotation each average 42 hours a week. If each person works 40 hours instead, it takes 4.2 people, so at least 5, with some working under 40. Multiply by the number of people you keep on shift, and add cover for time off.
Worked example: a site keeps 2 people on every day shift and 2 on every night shift, on 12-hour shifts. That is 2 × 168 = 336 hours of shifts a week. On DuPont, 4 crews of 2 make 8 people, each averaging 42 hours. At 40 hours each it would be 336 ÷ 40 = 8.4, so at least 9 people, some working under 40.
24/7 coverage with 3, 4, 5, 6, 7 or 8 employees
Hours each person works a week when the whole team shares 1 spot around the clock (168 hours ÷ people).
| Employees | Hours each a week | What it looks like |
|---|---|---|
| 3 | 56 | Every week averages 16 hours over 40 for each person. No 3-crew pattern is among the ready-made rotations. |
| 4 | 42 | The 4-crew rotations: 4 on 4 off, 2-2-3 (Pitman) and DuPont on 12-hour shifts, or Continental on 8-hour shifts. Each person averages 42 hours, and some weeks go over 40. |
| 5 | 33.6 | Room for time off. A 5-crew 12-hour loop (2 days, 2 nights, 6 off) averages 33.6 hours each; 6 on 4 off runs 5 crews on 10-hour earlies and lates and 8-hour nights, averaging 39.2 hours each. |
| 6 | 28 | Part-time hours each, or 1 person on every shift plus 2 to cover time off on a 4-crew rotation. |
| 7 | 24 | Part-time hours each. |
| 8 | 21 | Or 2 people on every shift on a 4-crew rotation, each averaging 42 hours. |
8-hour, 10-hour or 12-hour shifts for 24/7 coverage
Twelve-hour shifts need 2 shifts a day and 4 crews: DuPont, 2-2-3 (Pitman) and 4 on 4 off. Eight-hour shifts need 3 shifts a day; Continental covers them with 4 crews. The 6 on 4 off pattern uses 10-hour earlies and lates that overlap for 4 hours in the afternoon, with 8-hour nights, and takes 5 crews, so it needs 5 people for every person on shift instead of 4. Every crew in these rotations works every shift, so each crew is sized for your biggest shift.
Why some weeks go over 40 hours
The 4-crew rotations average 42 hours a week, but the hours are uneven from week to week. Overtime under the Fair Labor Standards Act is counted for each workweek of 168 hours, and the Department of Labor's Fact Sheet #23 says averaging hours over two or more weeks is not permitted. The calculator counts the weeks over 40 for the day your pay week starts. It counts hours, not pay: the free overtime calculator works out pay.
Cover for vacation, sick days and training
The headcount above adds nobody for time off. Enter how many shifts each person misses a year and the count grows until the shifts left to work cover the same hours. For reference, full-time US workers lost 1.7% of their usual hours to unplanned absence in 2025 (Bureau of Labor Statistics, Table 47). That figure leaves out vacation, so your own number is the one to use.
How to work out your 24/7 staffing
- 1Enter the people on shift. Say how many people you keep working at once on days and on nights. The page shows how many people it takes to cover every hour of every day.
- 2Pick your shift length. Compare 8, 10 and 12-hour shifts. Each card shows its own count for the same people on shift.
- 3Pick a rotation. Choose 4 on 4 off, 2-2-3 (Pitman), DuPont or 5 crews for 12-hour shifts, Continental for 8-hour shifts, or 6 on 4 off for 10-hour shifts. On 4 on 4 off and 2-2-3 you can keep each crew on days or on nights. The crews appear on a calendar from your start date, with the hours each crew works per pay week.
- 4Add cover for time off. Optional. Enter how many shifts each person misses a year for vacation, sick days and training, and the count grows to cover them.
- 5Paste your team and take it with you. Paste one name per line to fill the crews. Print it, download a spreadsheet or a phone calendar, copy a link to the numbers, or press Put your team on this rotation to open it in XShift AI.
24/7 coverage questions
- How many employees do I need to cover 24/7?
- A week has 168 hours. To keep 1 person on shift every hour, 4 people on a 4-crew rotation each average 42 hours a week. If each person works 40 hours instead, it takes 4.2 people, so at least 5, with some working under 40. Multiply by the number of people you keep on shift, and add cover for time off.
- How many employees do I need to cover 24/7 with 12-hour shifts?
- Four crews: 4 times the people on your biggest shift. With 2 on days and 2 on nights it takes 8 people, each averaging 42 hours a week, on 4 on 4 off, 2-2-3 (Pitman) or DuPont.
- How many employees do I need to cover 24/7 with 8-hour shifts?
- Three 8-hour shifts a day make 21 shifts a week for each person on shift. On the Continental rotation that is 4 crews, so 4 people for every person on shift, each averaging 42 hours a week.
- How many employees do I need to cover 24/7 with 10-hour shifts?
- The 6 on 4 off rotation uses 5 crews: 10-hour earlies and lates that overlap for 4 hours in the afternoon, and 8-hour nights. That is 5 people for every person on shift, each averaging 39.2 hours a week.
- Do fixed day and night crews take fewer people?
- Only when days and nights need different numbers. On a rotating pattern every crew works both, so each crew is sized for the bigger shift. With fixed crews, day crews are sized for days and night crews for nights: 3 on days and 1 on nights takes 12 people rotating and 8 fixed, on 4 on 4 off. With the same number on both shifts the count is the same.
- Why run 5 crews on 12-hour shifts?
- A fifth crew means more days off: on a loop of 2 days, 2 nights and 6 off, each person averages 33.6 hours a week instead of 42, which leaves room for training and cover. It takes 5 people for every person on shift instead of 4.
- Can 3 employees cover 24/7?
- Only with long weeks. 168 hours shared by 3 people is 56 hours each, every week, which is 16 hours over 40 on average.
- Why do some weeks go over 40 hours when the average is 42?
- 12-hour rotations put 3 or 4 shifts in some weeks and fewer in others. Overtime under federal law is counted week by week, and the Department of Labor says averaging hours over two or more weeks is not permitted. The calculator shows how many weeks go over 40 for the day your pay week starts.
- Does it include vacation and sick days?
- Not unless you add them. Press Add cover for time off and enter how many shifts each person misses a year. The page uses your number only.
- Does it work out overtime pay?
- No. It counts hours only. For pay, use the free overtime calculator.
- What happens to the names I paste?
- What you type may be kept in your browser and recorded by our analytics, advertising and session recording tools, as our Privacy Policy describes. Pressing Put your team on this rotation can send the names to us. If you then start a free trial, the names can be added to your team when your account opens, and they count as users on your plan after the trial. The Copy link button puts your numbers in the page address.
Also free: the DuPont schedule generator, the schedule generator, the overtime calculator and the rest of our free scheduling tools. More on rotations: rotating shift schedules guide.
Made by Noah Marbach, founder of XShift AI. Updated October 16, 2026.