Payroll
How to Calculate Hours Worked in Military Time (Including Overnight Shifts)
Step-by-step method to calculate hours worked from military time cards: subtract clock-in from clock-out, handle shifts past midnight, subtract breaks, total the week and convert to decimal hours.
By Free Military Time Calculator Team ·
To calculate hours worked in military time, subtract the clock-in time from the clock-out time, borrow 60 minutes when needed, and subtract unpaid breaks. A shift from 0700 to 1530 with a 30-minute lunch is 8 hours. Military time makes this easy: no AM/PM conversion is needed.
Step 1: Subtract Clock-In From Clock-Out
Subtract the hours and the minutes separately.
- 0700 to 1530: 15 h 30 min − 7 h 00 min = 8 h 30 min.
- 0845 to 1715: the minutes run short (15 is less than 45), so borrow 1 hour: 16 h 75 min − 8 h 45 min = 8 h 30 min.
Do not subtract the 4 digits as one number. 1715 − 845 = 870, which looks like 8 h 70 min and is wrong: an hour has 60 minutes, not 100.
Step 2: Handle Shifts That Cross Midnight
Add 24 hours to the clock-out time, if the clock-out time is earlier than the clock-in time.
- 2200 to 0630: 06:30 + 24:00 = 30:30 → 30:30 − 22:00 = 8 h 30 min.
- 1900 to 0700: 07:00 + 24:00 = 31:00 → 31:00 − 19:00 = 12 h.
Step 3: Subtract Unpaid Breaks
Subtract only unpaid time. Under U.S. Department of Labor rules for the Fair Labor Standards Act (FLSA), short breaks of 5 to 20 minutes are paid, and a meal period of 30 minutes or more is unpaid when the worker is fully relieved of duty.
- 8 h 30 min − 30 min lunch = 8 h 00 min.
Step 4: Total the Week
Add the daily totals. Add the minutes first and carry 1 hour for every 60 minutes.
| Day | In | Out | Break | Hours |
|---|---|---|---|---|
| Mon | 0700 | 1530 | 30 | 8:00 |
| Tue | 0700 | 1545 | 30 | 8:15 |
| Wed | 0700 | 1600 | 30 | 8:30 |
| Thu | 2200 | 0630 | 30 | 8:00 |
| Fri | 0700 | 1700 | 30 | 9:30 |
| Total | 42:15 |
Minutes: 0 + 15 + 30 + 0 + 30 = 75 → 1 h 15 min. Hours: 8 + 8 + 8 + 8 + 9 + 1 = 42. Total: 42 h 15 min.
Step 5: Convert to Decimal Hours
Divide the leftover minutes by 60: 15 ÷ 60 = 0.25, so 42 h 15 min is 42.25 hours. Payroll systems need this decimal form.
Step 6: Split Regular and Overtime Hours
Federal overtime starts after 40 hours in a workweek and pays at least 1.5 times the regular rate. 42.25 hours = 40 regular hours + 2.25 overtime hours. At $20.00 an hour: 40 × $20 + 2.25 × $30 = $800 + $67.50 = $867.50.
State rules can add daily overtime; California pays 1.5× after 8 hours in a workday.
Common Mistakes
- Base-10 subtraction of 4-digit times.
- Negative overnight shifts from forgetting to add 24 hours.
- Writing 8:15 as 8.15 instead of 8.25 in payroll.
- Subtracting paid breaks that should count as hours worked.
Let the Calculator Do It
The military time card calculator runs all 6 steps for a full week, including overnight shifts, breaks, overtime and gross pay.