Calculating Pay for 12-Hour Nursing Shifts
Many nurses work rotating 3x12 (three 12-hour shifts) or 4x12 (four 12-hour shifts) schedules instead of a standard five-day week. This makes it easy to lose track of exactly when overtime kicks in, especially with rotating days off, night shifts, and shift differentials layered on top.
Under federal law (FLSA), overtime for most hourly nurses is based on a 40-hour workweek, not a daily threshold. That means:
- A 3x12 schedule (36 hours/week) typically does not trigger overtime on its own.
- A 4x12 schedule (48 hours/week) puts 8 hours into overtime territory at 1.5x pay.
- Picking up an extra shift on top of your regular rotation can push you into overtime even in a "normal" week.
Use the calculator above to log each shift's start and end time (plus any unpaid meal break) and see your total regular hours, overtime hours, and projected gross pay.
Frequently Asked Questions (FAQ)
1. How many 12-hour shifts trigger overtime?
Under the standard federal 40-hour rule, your fourth 12-hour shift in a single workweek pushes you 8 hours into overtime (48 total hours - 40 = 8 hours at 1.5x pay). Three 12-hour shifts (36 hours) stay under the threshold.
2. Does this calculator include night shift differential?
Not automatically, since differential amounts vary a lot by employer and are often a flat dollar add-on or a percentage rather than a fixed rule. To approximate it, add your differential to your Base Hourly Rate before calculating (e.g., $35/hr base + $3/hr night differential = enter $38).
3. Is overtime calculated differently for nurses in California?
Yes. California adds daily overtime rules (1.5x after 8 hours in a single day, 2x after 12 hours) on top of the weekly 40-hour rule, which affects 12-hour shifts differently than the federal standard used here. Use our California Overtime Calculator for that.
4. Does this timesheet calculator save my personal data?
No. All calculations and inputs are processed locally within your own web browser. We do not store, collect, or share your work hours or financial information on external servers.
This page is for general information only and is not legal or payroll advice. Overtime rules can vary by state and employer contract — check with your HR department or your state's labor office for specifics.