How the hours are added up
For each day we take the end time minus the start time, then subtract the unpaid break. If the end time is earlier than the start (for example 10:00 PM to 6:00 AM), the shift is treated as running past midnight. The weekly total is shown both as hours:minutes and as decimal hours, which is what most payroll systems use — 7 hours 45 minutes is 7.75 hours.
Converting minutes to decimal hours
| Minutes | Decimal | Minutes | Decimal |
|---|---|---|---|
| 6 | 0.10 | 36 | 0.60 |
| 15 | 0.25 | 45 | 0.75 |
| 20 | 0.33 | 48 | 0.80 |
| 30 | 0.50 | 54 | 0.90 |
Divide the minutes by 60. That is all the conversion is.
Overtime
Under the U.S. Fair Labor Standards Act, non-exempt employees must be paid at least one and a half times their regular rate for hours worked over 40 in a workweek. Some states add daily overtime — California, for example, also requires overtime after 8 hours in a day — so check your state’s rules. This calculator applies the weekly threshold you enter.
Rounding
Some employers round punches to the nearest 6 or 15 minutes. The U.S. Department of Labor allows rounding only if, over time, it doesn’t shortchange employees. Leave rounding off if you want the exact figure.
Frequently asked questions
How do I calculate hours worked with a lunch break?
Subtract the start time from the end time, then subtract the unpaid break. 9:00 to 17:30 with a 30-minute lunch is 8 hours.
What is 37.5 hours in hours and minutes?
37 hours 30 minutes.
Is my data saved?
Your entries are kept in this browser only, so a refresh doesn’t lose them. Nothing is uploaded.
Sources
- U.S. Department of Labor — Overtime Pay (FLSA)
- 29 CFR 785.48 — Rounding of time records
- California Labor Code § 510 — daily overtime
Last reviewed 2026-10-14.