Time Duration Calculator

Reviewed

Enter details
ResultUpdates as you type
Duration510Duration hint
Total minutes510
Total seconds30,600
Decimal hours
8.5

Calculate the duration between two times in hours, minutes and seconds. Handles overnight time spans automatically.

Enter a start time and an end time in HH:MM format to see the elapsed duration. Overnight spans are handled automatically.

A time duration calculator works out the elapsed time between two clock times. Enter start and end times in 24-hour HH:MM format and the calculator instantly shows the duration in hours and minutes, total minutes and total seconds.

It automatically handles overnight spans — if you enter 23:00 as the start and 02:00 as the end, it correctly calculates 3 hours across midnight. The decimal hours breakdown is useful for timesheet calculations and billing.

This tool is handy for tracking work hours, calculating travel time, measuring cooking or exercise duration, and billing by the hour.

How to use

  1. Enter the start time in HH:MM (24-hour format).
  2. Enter the end time.
  3. Read the duration in hours and minutes below.

Formula

Duration is the difference between end and start times.

DurationDuration = End time − Start time
OvernightIf End < Start, Duration = (End + 24:00) − Start

Worked examples

9:00 to 17:30

From 9:00 AM to 5:30 PM is 8 hours 30 minutes (510 total minutes).

23:00 to 02:00 (overnight)

From 23:00 to 02:00 crosses midnight and gives 3 hours (180 minutes).

Frequently asked questions

How do I calculate time duration?

Enter the start time and end time in HH:MM format. The calculator finds the difference in hours and minutes, handling overnight spans automatically.

Does it handle overnight time spans?

Yes. If the end time is earlier than the start time (e.g. 23:00 to 02:00), the calculator assumes the span crosses midnight and gives you 3 hours.

Can I use 12-hour format?

Enter times in 24-hour format (e.g. 2:30 PM = 14:30). This avoids AM/PM confusion.

How do I convert minutes to hours and minutes?

Divide total minutes by 60. The quotient is hours, the remainder is minutes. For example, 150 minutes = 2 hours 30 minutes.

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