Work Decision Reference
The core formulas, units and comparison conventions used across Work Decisions UK, collected in one place so the assumptions are easy to inspect.
Money basis: gross versus take-home
Use gross pay where the question is specifically about a contractual rate or premium before deductions, such as overtime pay or a shift allowance. Use expected take-home change where the decision compares disposable income with personal costs, such as a longer commute. Work Decisions does not convert one into the other automatically because personal tax and deduction circumstances vary.
Core formulas
| Question | Reference calculation |
|---|---|
| Overtime total | base hourly rate × multiplier × overtime hours |
| Overtime premium extra | base rate × (multiplier − 1) × overtime hours |
| Percentage shift premium | base rate × premium % × eligible hours |
| Annualise a weekly figure | weekly amount × working weeks entered |
| Extra commute days | extra office days/week × working weeks |
| Commute hours | commute days × round-trip minutes ÷ 60 |
| Leave package hours | leave days entered × normal paid hours per leave day |
| Job comparison value | take-home + employer pension value − recurring work costs |
| Committed hours | (paid hours/week + regular unpaid/commute hours/week) × working weeks |
Working weeks
Many comparisons ask you to enter working weeks rather than hard-coding 52. This prevents a daily commute or childcare cost being multiplied through weeks when you expect to be on leave or otherwise not making that journey. Use the same basis when comparing alternatives.
Repeating-rota reference
| Preset | Defined sequence | Length | Work positions | Cycle work share |
|---|---|---|---|---|
| 4 on / 4 off | WWWWOOOO | 8 days | 4 | 50% |
| 2 days / 2 nights / 4 off | DDNNOOOO | 8 days | 4 | 50% |
| 2-2-3 preset | WWOOWWWOOWWOOO | 14 days | 7 | 50% |
Exact yearly shift counts depend on the anchor date and calendar boundaries. The annual shift calculator repeats the entered sequence across the requested year rather than assuming an abstract 365 × percentage result is exact.
What this reference deliberately does not contain
- personal income-tax or National Insurance calculations;
- a universal overtime or shift-premium rate;
- a statutory holiday entitlement engine;
- legal interpretations of contracts, working-time rules or leave approval.
Those areas depend on personal circumstances, contractual terms or changing official rules. Where relevant, calculator pages and guides point to official sources.