Time Duration Calculator — Hours Between Two Times
Duration between two times
—
hours : minutes
—
decimal hours
—
total minutes
The end time is earlier than the start, so this is counted as an overnight span crossing midnight.
Add or subtract a duration
—
(+1 day)
resulting time
Enter a start and end time to get the duration between them in hours and minutes, total minutes, and decimal hours — the format payroll systems expect. Overnight shifts are handled automatically, and an optional break deduction makes it a one-step timesheet calculator. A second panel adds or subtracts a duration from any time of day.
How it works
- 1 Enter start and end times Pick the two times of day. If the end time is earlier than the start, the calculator assumes the period crosses midnight — a night shift from 22:00 to 06:00 is 8 hours.
- 2 Deduct a break if needed Type unpaid break minutes (30, 45, 60…) and they're subtracted from the total — so 9:00 to 17:30 with a 30-minute lunch shows 8 hours worked.
- 3 Add or subtract a duration In the second panel, pick a start time, choose add or subtract, and enter hours and minutes. You get the resulting clock time, with a day marker if it lands on the previous or next day.
Your data stays private
All processing happens entirely in your browser. No files, text, or data are ever sent to our servers. You can disconnect from the internet and this tool will still work.
Frequently asked questions
- How do I calculate hours worked between two times?
- Convert both times to minutes since midnight, subtract, and divide by 60. From 9:00 to 17:30 is 510 minutes, or 8 hours 30 minutes. Subtract unpaid breaks to get payable hours — the calculator does all of this in one step.
- What are decimal hours and why do timesheets use them?
- Decimal hours express minutes as a fraction of an hour: 8 hours 30 minutes is 8.5, and 7 hours 45 minutes is 7.75. Payroll multiplies decimal hours by an hourly rate, which is why timesheet software asks for 8.25 rather than 8:15. The two formats are easy to confuse — 8.15 decimal hours is actually 8:09.
- How are overnight shifts handled?
- If the end time is earlier than the start time, the calculator assumes you crossed midnight and adds 24 hours. A shift from 22:00 to 06:00 counts as 8 hours, and a note tells you the span is overnight.
- Can I add hours to a time and land on another day?
- Yes. Adding 10 hours to 20:00 gives 06:00 with a +1 day marker; subtracting 3 hours from 01:00 gives 22:00 the previous day. The day offset is shown next to the result whenever it isn't zero.
- Is anything sent to a server?
- No. The arithmetic runs entirely in your browser — times are never uploaded, stored, or tracked.
From the blog
Timesheet Math: Decimal Hours, Breaks, and Night Shifts Why 8:15 on the clock is 8.25 on the payslip, how to handle shifts that cross midnight, and the rounding rules that quietly change your hours. Read the post →Related tools
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