Time Duration Calculator
Calculate the exact duration between two times. Add and subtract time. Convert hours:minutes to decimal and back. Free.
How to use
Three time duration modes
"Between two times" calculates the gap between start and end, minus any break. "Add/subtract" adds or removes hours and minutes from any time. "Decimal hours" converts between 3:45 and 3.75 — useful for invoicing and payroll.
Overnight durations
If the end time is earlier than the start time (e.g. a night shift: 22:00 to 06:00), the calculator automatically detects an overnight duration and adds 24 hours to give the correct result.
Frequently asked questions
Is the Time Duration free to use?
Yes, the Time Duration is completely free. There is no sign-up, no account required, and no limit on how often you can use it.
Does the Time Duration use my time zone?
Yes, the Time Duration uses your device's local time zone by default. You can also work with dates explicitly without time zone effects where applicable.
What devices does the Time Duration work on?
The Time Duration works on any device with a modern web browser — desktop, laptop, tablet, or phone. It is mobile-friendly and works offline once the page has loaded.