Hours Calculator
Find how much time passes between a start and end time.
Work out how long something lasted. Enter a start and end time (HH:MM) to get the duration in hours and minutes — it even handles shifts that run past midnight.
Formula / method
Examples
8h 30m
8h 0m
Why time maths trips people up
Time runs in base 60, not base 10, so 30 minutes is 0.5 of an hour rather than 0.30. This tool converts your start and end times into a clean decimal total, which is exactly what you need to multiply by an hourly rate for pay.
Breaks and overnight shifts
For accurate totals, decide whether breaks are paid and subtract any unpaid ones. Shifts that cross midnight need care because the end time looks smaller than the start; adding 24 hours to the end before subtracting handles it correctly. The related guide walks through both cases with worked examples.
Where it's used
- Totaling worked hours from a timesheet to calculate wages
- Adding up billable hours for freelance or consulting invoices
- Checking how long an overnight shift lasted for shift-work pay
- Measuring study, practice, or focus sessions logged by start and end time
- Working out cooking, charging, or fasting windows such as a 16:8 schedule
Real-world examples
- A barista clocking in at 08:15 and out at 16:45 works 8h 30m, or 8.5 hours to multiply by an hourly rate.
- A night-shift nurse starting at 22:00 and finishing at 06:00 gets 8h 0m, with the calculator wrapping past midnight.
- A tutor logging 13:20 to 17:50 records 4h 30m, or 4.5 decimal hours for billing.
Did you know?
We split an hour into 60 minutes and a minute into 60 seconds because of the base-60 (sexagesimal) counting system used by the ancient Babylonians thousands of years ago.
FAQ
Does it handle overnight shifts?
Yes. If the end time is earlier than the start time, it assumes the period crosses midnight and adds 24 hours.