What Is Time Duration Calculator?

A free online time duration calculator. Enter a start and end time to see the exact duration between them in hours:minutes:seconds format. Also shows total decimal hours, total minutes, and total seconds. The calculator handles overnight durations (when end time is before start time). Toggle optional seconds precision for finer measurements. Ideal for tracking meeting lengths, shift durations, travel time, cooking timers, and productivity sessions — all running locally in your browser with no sign-up.

Why Use Time Duration Calculator?

  • Overnight duration support (end before start)
  • Shows duration in HH:MM:SS, decimal hours, total minutes, and total seconds
  • Optional seconds precision toggle
  • Real-time calculation updates as you type

How to Use Time Duration Calculator — Step by Step

1

Enter the start time using the time picker.

2

Enter the end time — overnight is handled automatically.

3

Toggle seconds precision if needed.

4

View the duration in HH:MM:SS, decimal hours, total minutes, and total seconds.

Who Is Time Duration Calculator Best For?

  • meeting duration tracking
  • shift time calculation
  • travel time estimation
  • productivity session timing

Time Duration Calculator — Frequently Asked Questions

What happens if the end time is before the start time?

The calculator automatically detects overnight periods and adds 24 hours to the duration. For example, 22:00 to 06:00 gives 8 hours.

How precise is the calculation?

The tool calculates to the second when seconds mode is enabled. The default mode shows hours and minutes. Decimal hours are shown to 4 decimal places.

Ready to Use Time Duration Calculator?

Free online tool — works in your browser, no sign-up required. Start using it right now.

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