Time Duration Calculator
Calculate the exact duration between two clock times.
How to Calculate Time Duration
- Enter a start time and an end time.
- The duration between them updates instantly, in hours and minutes plus decimal hours.
- If the end time is earlier than the start time, it's assumed to be the next day.
Frequently Asked Questions
How does this handle a shift that crosses midnight?
If the end time is earlier than the start time, the calculator assumes the end time falls on the next day — so a start of 10:00 PM and an end of 6:00 AM correctly gives 8 hours, not a negative duration.
What is "decimal hours" used for?
It expresses the duration as a single decimal number (like 7.5 instead of 7 hours 30 minutes), which is the format most timesheet and payroll systems expect for calculating pay from hours worked.
Can I calculate a span longer than 24 hours?
This tool is built for a single start and end clock time within a day (or overnight into the next day) — for spans of multiple full days, use the Date Difference Calculator instead, which handles calendar dates directly.
Is my data sent anywhere?
No — the calculation happens entirely in your browser using JavaScript, so nothing you enter is ever sent to a server.