Calculate weekly and annual pay for 12-hour shifts with overtime after 40 hours/week.
Formula: Weekly Hours = Shifts × 12 OT Hours = max(0, Weekly Hours − 40) Regular Pay = min(Weekly Hours, 40) × Rate OT Pay = OT Hours × Rate × OT Multiplier
Twelve-hour shifts have become the default in hospitals, oil refineries, and emergency services because they let an employer cover 24-hour operations with fewer crew handoffs and give workers more consecutive days off. The pay math is where it gets interesting: a typical 12-hour schedule produces 36 to 60 hours per week depending on rotation, with overtime triggered above 40 in most states and shift differentials layered on top for nights and weekends.
The four common 12-hour schedule patterns
3-on / 3-off rotating (36 hours/week): The simplest pattern, no built-in overtime. Common for hospital nurses who pick up shifts to reach full-time hours.
DuPont (averages 42 hours/week): Four-week cycle of 4-on/4-off through day and night shifts. Built-in 2 hours of weekly overtime for the worker; favored in refineries.
Pitman (42 hours/week average): 2-3-2 repeating across 14 days. Every other weekend is off. Standard in public safety with 4 teams covering 24/7.
Panama (42 hours/week average): 2-2-3 across 14 days. Similar coverage profile to Pitman but with different days-off cadence.
Custom 48 or 60 hours: Some manufacturing and oilfield jobs run 4-on or 5-on at 12 hours, which produces 8 to 20 hours of weekly overtime — a major income amplifier.
FLSA overtime rules in plain English
The federal Fair Labor Standards Act requires non-exempt employees to be paid at least 1.5 times their regular rate for hours worked above 40 in a single workweek. The workweek is a fixed, recurring 7-day period; it does not have to start on Sunday. Important nuances:
Salaried non-exempt workers are still eligible for overtime — exempt status depends on job duties and salary level, not just being on a salary.
Overtime cannot be averaged across multiple workweeks. Each week stands alone.
Shift differential is included in the "regular rate" when computing the OT multiplier in most circumstances — failing to do so is a common payroll error.
States that require daily overtime
California: 1.5x after 8 hours/day, 2x after 12 hours/day. 1.5x for the first 8 hours on the 7th consecutive day of work; 2x beyond that.
Alaska: 1.5x after 8 hours/day.
Nevada: 1.5x after 8 hours/day for employees earning less than 1.5x the state minimum wage.
Colorado: 1.5x after 12 hours/day or 40 hours/week, whichever is greater.
Oregon and Washington: Industry-specific rules for manufacturing and certain agricultural operations.
For a 12-hour shift in California, expect 4 hours at 1.5x and any time past 12 at 2x — a single shift can deliver 8 + 6 + 0 = 14 hours of pay before stepping into a second day.
Night-shift differential — how much is fair
Healthcare: $2.00 to $4.00 per hour above day rate for 7pm-7am shifts
Manufacturing: $1.50 to $3.00 per hour or 10% premium
Federal employees (Title 5): 10% premium for regularly-scheduled night work
Public safety (police/fire): Often via union contract at $1.50 to $5.00 per hour
Retail/hospitality: Less common but $1 to $2 per hour at large chains
Walkthrough: a $32/hour ICU nurse on a 3-shift Pitman rotation
Base rate: $32/hour
Shifts: 3 per week × 12 hours = 36 hours regular time
Night differential: $3/hour × 2 night shifts × 12 hours = $72/week extra
Weekly gross at no overtime: $32 × 36 + $72 = $1,224
Pick up one extra 12-hour shift → 48 total hours, 8 of which are overtime
OT pay: $32 × 1.5 × 8 = $384 (plus differential on those hours if night)
New weekly gross: $32 × 40 + $384 + $72 = $1,736
Annualized: ~$90,272 (assuming 52 weeks with consistent overtime pickup)
Tax handling — is OT really worth less after tax?
A persistent myth says overtime is "taxed at a higher rate" and therefore not worth working. It isn't. All wages are taxed at the same marginal rates. What can happen on a single paycheck is that withholding tables assume the higher-than-normal weekly amount is your steady income, so they withhold at a higher bracket — but you receive any excess back on your annual tax return. The economic value of OT is genuinely 1.5x your normal rate (minus the same percentage of taxes), so it is always worth more dollar-for-hour than a standard hour.
Frequently asked questions
Can I refuse mandatory overtime on a 12-hour schedule?
Under federal law, no — non-exempt employees can be required to work overtime as a condition of employment, as long as they're paid the OT premium. Some state laws (notably California's healthcare-specific rules and Pennsylvania's mandatory-overtime restrictions in nursing) limit this; check your state and any union contract.
Are breaks paid on a 12-hour shift?
Federal law does not require any paid breaks, though most employers provide them. Short rest breaks (5 to 20 minutes) must be paid if offered; meal breaks (30+ minutes) can be unpaid if the employee is fully relieved of duties.
How is overtime calculated if my hourly rate changes during the week?
The "regular rate" for that workweek is total straight-time earnings divided by total hours, and overtime is 1.5x that blended rate. This is why night differential pushes your effective OT rate higher than 1.5x your base.
What about double-time on holidays?
Federal law does not require holiday or weekend premium pay; it's set by employer policy or union contract. Many hospitals and unionized manufacturers pay 1.5x or 2x for holiday shifts.
Do salaried 12-hour-shift workers get overtime?
Only if they're non-exempt. The 2024 FLSA salary threshold (recently updated) sets the floor for exempt classification; salaried workers below that level must receive overtime regardless of being salaried.
How is on-call time paid?
If you must remain on the employer's premises or so close that personal time is restricted, on-call time is generally compensable. If you can be elsewhere and only must respond within a reasonable window, on-call may not be compensable except for actual call-in time.
Educational use; verify state and union rules before relying on calculations for legal or HR purposes. Reviewed by Marcus Tan, CPA, on February 24, 2026.