Time Duration Calculator – Complete Guide & Free Online Tool
A time duration calculator finds the hours, minutes and seconds between a start and end time (24-hour HH:MM format). Free online tool included.
Published 2026-09-13
What is Time Duration Calculator?
A time duration calculator finds the hours, minutes and seconds between a start and end time (24-hour HH:MM format).
How it works
Times are entered in 24-hour HH:MM (or HH:MM:SS) format and converted to seconds, then the difference is converted back to hours, minutes and seconds.
Key Features
• Hours • minutes • seconds • 24-hour format • Clear errors
Examples
• From 09:30 to 17:45 is 8 hours 15 minutes.
Common Use Cases
• Work shifts • Meeting durations • Schedule planning
Tips & Best Practices
• Use 24-hour format to avoid AM/PM ambiguity.
Limitations
• For overnight spans • enter times as dates instead.
External Resources
Wikipedia: Time