Time duration calculator — hours between two times
Enter a start and end time and read the duration two ways: hours and minutes, and decimal hours — 7:30 is 7.50, which is the form payroll systems want. An end time before the start is read as crossing midnight, so overnight shifts work without tricks.
Why decimal hours exist
Payroll multiplies hours by a rate, and multiplication wants one number, not two. So timesheet systems store hours as decimals, and the conversion between "7 hours 30 minutes" and "7.50" is where the errors live: 7.30 typed into a rate calculation silently means 7 hours 18 minutes. The calculator shows both forms side by side so the right one gets copied.
The other half of the job is spans that cross midnight. Clock arithmetic that subtracts start from end goes negative at 22:00–06:00; the tool reads that ordering as an overnight span and says so in the result, because a silent assumption is how a night shift becomes negative sixteen hours on an invoice.
How to use this
- Enter the start and end times in 24-hour form.
- Read the duration as hours:minutes and as decimal hours — payroll wants the decimal.
- Add a break in minutes to subtract it from the total.
Worth knowing: The calculation is within one 24-hour cycle. For durations spanning several days, count the days with the days-between tool and add the clock time on top.
FAQ
How do I convert minutes to decimal hours?
Divide the minutes by 60 and keep two decimals: 15 minutes is 0.25, 30 is 0.50, 45 is 0.75, and 7 hours 20 minutes is 7.33. The calculator shows this automatically because writing 7.30 for 7:30 — the most common timesheet error — underpays twenty minutes.
What about a shift that crosses midnight?
Enter it as it happened: start 22:00, end 06:00. An end time earlier than the start is read as the next day, giving 8 hours, and the result says that assumption out loud.
Can I subtract a lunch break?
Yes — the break field takes minutes and comes off the total. A 09:00–17:30 day with a 30-minute break is 8 hours, or 8.00 decimal.