Work / Rest Cycle Calculator
A work/rest pattern only works if the ratio of working days to off days can support the number of people required every day. This calculator does that math before you build the roster.
Enter your scheduling assumptions
Change the inputs and the result updates immediately. Keep the assumptions realistic—the output is only as useful as the staffing model you give it.
| Pattern | Work ratio | Staff needed | Reserve after coverage | Status |
|---|---|---|---|---|
| 4 on / 2 off | 67% | 32 | -1 | Short |
| 4 on / 3 off | 57% | 37 | -6 | Short |
| 5 on / 2 off | 71% | 30 | 1 | Feasible |
| 3 on / 3 off | 50% | 42 | -11 | Short |
| 2-2-3 / Panama | 50% | 42 | -11 | Short |
The required headcount is based on the work/off ratio sustaining the same daily staffing requirement. Real schedules still need person-level constraints checked.
Method
For each repeating pattern, required staff = people required every day × cycle length ÷ working days in the cycle, rounded up to a whole person.
Example
A 4-on/2-off pattern works 4 of every 6 days, so sustaining 10 people working every day requires at least 15 people before reserve or other constraints.
What the answer means
A passing result means the arithmetic has enough capacity. It does not mean every individual assignment will be qualified, conflict-free, rested, or operationally sensible.
What this tool does not prove
The ratio check does not decide whether a rotation is appropriate for a particular occupation, jurisdiction, fatigue-risk program, or collective bargaining agreement.
Answer the planning question before assigning names
Compare common work/rest rotations against your available staff and daily staffing requirement to see which cycles are sustainable.
See how many people each recurring rotation requires.
Compare the reserve left over after minimum staffing is met.
Avoid choosing a rotation that looks attractive but cannot sustain daily coverage.
Capacity math cannot see every person-level scheduling constraint
A staffing model can be mathematically feasible and still fail when only certain people are qualified for a role, approved absences remove key people, assignments overlap, rest windows are too short, or coverage changes on specific dates. Those are the checks RoleSchedule keeps attached to the schedule itself.