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Date & Time Tools

Time Duration Calculator

Find the duration between two clock times in hours and minutes, decimal hours and total minutes.

  • 8h 30mDuration
  • 8.50Decimal hours
  • 510Total minutes

If the end time is earlier than the start, it is treated as the next day.

How to use it

  1. Enter the start time In 24-hour HH:MM format.
  2. Enter the end time Earlier than the start means overnight.
  3. Read the duration Hours and minutes, plus decimal hours.

Examples

09:00 to 17:30 8h 30m
decimal 8.5

About this tool

Working out how long something lasted shouldn’t need finger-counting across the hours. Enter a start and end time and this calculator returns the duration in hours and minutes, as decimal hours, and as a total number of minutes.

It automatically handles spans that cross midnight, so overnight shifts and late sessions just work. The decimal-hours figure is especially useful for timesheets. Everything is computed in your browser.

Frequently asked questions

Does it handle overnight times?

Yes. If the end time is earlier than the start, it assumes the span crosses midnight, so 22:00 to 06:00 returns 8 hours.

What are decimal hours for?

Decimal hours (like 8.5) are handy for timesheets and billing, where time is often recorded as a fraction of an hour.

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Updated June 14, 2026