Time Duration Calculator
Enter a start time and end time to see the exact duration between them, in hours and minutes.
If the end time is earlier than the start time, it’s assumed to be the next day.
Duration
8h 30m
Total minutes
510
Decimal hours
8.5
How to use the Time Duration Calculator
- Enter a start time.
- Enter an end time.
- See the duration instantly, in hours and minutes, total minutes, and decimal hours.
What is a time duration calculator?
A time duration calculator works out how much time passes between a start time and an end time on a 24-hour clock, showing the result in hours and minutes, total minutes, and decimal hours (handy for timesheets).
How the calculation works
Both times are converted to minutes since midnight, and the start is subtracted from the end. If the end time is earlier in the day than the start time (like a night shift from 22:00 to 02:00), the calculator assumes the end time falls on the next day and adds 24 hours automatically.
Worked example
A shift from 09:00 to 17:30 lasts 8 hours 30 minutes (510 minutes, or 8.5 decimal hours).
Understanding your result
- Duration is shown in whole hours and minutes.
- Total minutes is the same duration as a single number.
- Decimal hours converts minutes into a fraction of an hour, useful for payroll or billing.
Common uses
People use this to calculate work shift lengths (including overnight shifts), time spent on a task, meeting durations, or any other time-of-day interval.
Important notes
This calculator works with times of day (not dates), on a 24-hour clock. For a duration spanning multiple calendar days, use the Date Difference Calculator instead.
Frequently asked questions
What is a time duration calculator used for?
It's used to find how much time passes between two times of day — for shifts, tasks, meetings, or any time interval.
How does it handle overnight shifts?
If the end time is earlier than the start time, the calculator assumes it falls on the next day and calculates the duration accordingly.
What are decimal hours?
Decimal hours express minutes as a fraction of an hour — for example, 30 minutes is 0.5 decimal hours. This is commonly used for timesheets and billing.
Can I use this for dates spanning more than 24 hours?
No, this calculator handles times of day within a single day-to-next-day span. For multi-day durations, use the Date Difference Calculator.