Methodology & Sources

1. Paid hours per shift

paid hours = scheduled shift length − unpaid break minutes ÷ 60

A 12-hour shift with a 30-minute unpaid meal break pays 11.5 hours. You control the break deduction in every calculator because facilities differ (some deduct 60 minutes, some pay shorter breaks).

2. Overtime — two US models

Federal weekly (FLSA)

Hours beyond 40 in a workweek earn 1.5× the regular rate (US DOL Fact Sheet #22). Our weekly projections allocate the 40-hour budget across your actual rotation, shift by shift, and reset the budget each Monday. Three 12s (34.5 paid hours) never crosses it; a fourth shift usually does.

California daily

California pays daily overtime: 1.5× after 8 hours in a day, 2× after 12 (CA DIR overtime FAQ). Every 12-hour shift therefore contains 4 daily-overtime hours (3.5 paid-OT hours after a 30-minute break) even in a 3-shift week. A handful of other states (e.g. Alaska, Nevada, and Colorado with its own thresholds) have daily rules — we model the California rule as the daily-OT family's template.

3. Differentials & premiums

Night differentials and weekend premiums are applied as a percentage of your base rate across the paid hours of a qualifying shift. Real policies usually define exact qualifying clock windows (for example 19:00–07:00), so treat our whole-shift model as an approximation — the differential calculator exists precisely to sanity-check that line on your stub.

Under FLSA, shift differentials are generally part of the regular rate used for overtime — meaning your OT hours are worth slightly more than base × 1.5. We show differentials as a separate line rather than folding them in, so you can verify both parts independently.

4. Rotation math

Each pattern (Pitman/2-2-3, DuPont, 4-on 4-off) is a fixed cycle of day codes anchored to the start date you enter: your calendar position is (days since your cycle start) mod cycle length. Fixed 3×12 schedules are generated from the weekdays you pick. All date math uses local calendar dates and is DST-safe. Calendars are estimates of the published pattern — your facility's posted schedule always wins.

5. What we deliberately exclude

• Taxes — gross pay only; withholding varies too much to estimate usefully.
• Shift differentials folded into OT regular rate — shown separately instead (see §3).
• Collective bargaining agreements, incentive pay, on-call and call-back rules — too facility-specific.

6. Privacy

Rosters, rates and preferences are stored in your browser's localStorage. We have no accounts, no database of user data, and nothing to sell. Clearing site data erases everything.

FAQ

Is ShiftLife Hub payroll or legal advice?

No. Every number on this site is a planning estimate. Your employer payroll system, union contract and state rules control what actually lands in your bank account. When estimates and your paycheck disagree, your paycheck (and your payroll department) wins.

Why does my paycheck differ from the calculator?

The most common reasons: a different unpaid-break deduction, premium pay folded into the regular rate differently, employer-specific rules like the 8/80 hospital plan, retro active raises, or taxes — which this calculator intentionally excludes.

What is the 8/80 rule for hospitals?

Some hospitals and care institutions elect the 8/80 system under FLSA: overtime after 8 hours in a day OR 80 hours in a 14-day period, whichever benefits the employee more. This calculator models plain weekly and daily rules; ask payroll which system applies to you.

Primary sources: US Department of Labor — FLSA Overtime Fact Sheet #22 · California DIR — Overtime FAQ. Rules change; verify against current official guidance.