Work Hours Calculator
Add up your daily and weekly work hours, subtract unpaid breaks, and calculate regular vs. overtime hours with estimated gross pay. Built for employees, freelancers, and payroll managers needing instant, accurate timesheet totals.
Total Work Hours
35:00
35.00 decimal hrs
Regular Hours
35:00
35.00 decimal hrs
Overtime Hours
0:00
0.00 decimal hrs
Days Worked
5 days
Avg: 7:00/day (7.00h)
Overtime threshold: 40 hours/week (Multiplier: 1.5x). Calculations update automatically.
How to Calculate Work Hours: Formulas & Methodology
Calculating hours worked seems straightforward, but handling unpaid lunch breaks, shifts crossing midnight, and converting minutes to decimal hours for payroll frequently leads to errors. Here is the mathematical framework used by payroll systems and this calculator:
1. Standard Daily Shift Formula
Subtract your shift start time from your end time in minutes, then deduct unpaid break minutes:
Example: 09:00 to 17:00 (480 mins) minus 60-min lunch = 420 mins (7.0 hrs).
2. Overnight Shift (Crosses Midnight)
When the end time is numerically less than the start time, 24 hours (1,440 minutes) are added to account for crossing midnight:
Example: 22:00 to 06:00 (8h span) minus 30-min break = 7.5 hrs (7h 30m).
3. Converting Minutes to Decimal Hours
Payroll software cannot process hours and minutes directly. Minutes must be converted to decimals by dividing by 60:
Example: 7 hours and 45 minutes = 7 + (45 ÷ 60) = 7.75 decimal hours.
4. Weekly Overtime & Pay Calculation
Hours worked above the 40-hour threshold are paid at the overtime rate (typically 1.5x):
Example: 46 hours @ $20/hr = (40 × $20) + (6 × $20 × 1.5) = $800 + $180 = $980.
Minutes to Decimal Hours Conversion Chart
Standard reference chart for translating punch-clock minutes into payroll decimal hours.
| Minutes | Decimal |
|---|---|
| 5 min | 0.08 |
| 10 min | 0.17 |
| 15 min | 0.25 |
| Minutes | Decimal |
|---|---|
| 20 min | 0.33 |
| 25 min | 0.42 |
| 30 min | 0.50 |
| Minutes | Decimal |
|---|---|
| 35 min | 0.58 |
| 40 min | 0.67 |
| 45 min | 0.75 |
| Minutes | Decimal |
|---|---|
| 50 min | 0.83 |
| 55 min | 0.92 |
| 60 min | 1.00 |
Real-World Worked Examples
Compare standard workplace scenarios to understand how break deductions, overnight hours, and overtime multipliers affect final timesheet summaries.
Standard 40-Hour Full-Time Week
5 days (Mon–Fri), 08:30 to 17:00 with a 30-minute unpaid lunch break each day.
48-Hour Extended Workweek (1.5x OT)
6 days (Mon–Sat), 08:00 to 16:30 with 30-min unpaid lunch (8h/day × 6 days).
12-Hour Overnight Shift (Cross-Midnight)
3 shifts (Fri–Sun), 19:00 to 07:30 next morning with 45-min unpaid break.
Variable Part-Time Schedule
4 shifts with irregular start times: 4.5h, 6h, 8h, and 5h with differing breaks.
FLSA Overtime Compliance & Time Clock Rounding Rules
Under the United States Fair Labor Standards Act (FLSA), covered non-exempt employees must receive overtime pay for hours worked exceeding 40 in a single workweek. A workweek is defined as a fixed and regularly recurring period of 168 hours (seven consecutive 24-hour periods). The law does not require overtime pay for work on Saturdays, Sundays, holidays, or regular days of rest, unless hours exceed 40 for the workweek.
The 7-Minute Rounding Rule (29 CFR § 785.48(b))
Federal regulations allow employers to record time using 15-minute intervals. Under the 7-minute rule:
- Minutes 1 through 7 round down to the nearest quarter hour (e.g. 09:07 rounds to 09:00).
- Minutes 8 through 14 round up to the nearest quarter hour (e.g. 09:08 rounds to 09:15).
- Rounding must average out over time so that it does not consistently underpay employees for time worked.
Note: Certain states (such as California, Nevada, and Alaska) mandate daily overtime after 8 hours worked in a single day, regardless of weekly totals. Shiftfy allows you to track both weekly thresholds and review each daily subtotal to ensure compliance with state and local employment laws.
Frequently Asked Questions
Answers to common questions regarding work hours, break deduction rules, and payroll calculations.
How do I calculate total work hours for a day?
Subtract your start time from your end time, then subtract any unpaid lunch or break time. For example, starting at 09:00 and finishing at 17:30 with a 30-minute unpaid lunch equals 8 hours and 30 minutes minus 30 minutes, resulting in 8.00 hours worked.
How does this calculator handle overnight shifts that cross midnight?
If your shift end time is earlier than your start time (for instance, starting at 22:00 / 10:00 PM and ending at 06:00 / 6:00 AM the next day), the calculator automatically detects that the shift crosses midnight and adds 24 hours to calculate the correct duration.
How do I convert minutes into decimal hours for payroll?
Divide the number of minutes by 60. For example, 15 minutes is 15 ÷ 60 = 0.25 hours, 30 minutes is 30 ÷ 60 = 0.50 hours, and 45 minutes is 45 ÷ 60 = 0.75 hours. The calculator displays both traditional HH:MM and decimal hours automatically.
How is weekly overtime calculated?
Under the US Fair Labor Standards Act (FLSA), non-exempt employees must receive overtime pay for hours worked over 40 in a workweek at a rate not less than 1.5 times their regular rate of pay. Shiftfy allows you to customize the weekly threshold (default 40 hours) and the overtime multiplier (default 1.5x).
Can I enter multiple breaks for a single workday?
Yes. Simply sum up all unpaid break durations throughout your day and enter the total in the Break (min) input. For example, a 15-minute unpaid morning break plus a 30-minute unpaid lunch equals 45 minutes total break time.
What is the 7-minute rounding rule?
Under federal law (29 CFR § 785.48(b)), employers may round employee time to the nearest 15-minute increment using the 7-minute rule: times between 1 and 7 minutes round down to the previous 15-minute mark, while times between 8 and 14 minutes round up to the next 15-minute mark.
Is my payroll or hours data stored on your servers?
No. All calculations are executed 100% locally in your web browser. Shiftfy transmits zero timesheet data to any external server. Your entries are saved locally to your device's browser memory (localStorage) so you can return to them later without losing your work.
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