Clock Duration Calculator

Calculate the exact duration between two times, supporting both 12-hour and 24-hour formats.

: :
: :

Time Difference:

8 hr 0 min

How to Calculate Time Duration

Knowing the exact duration between two points in time is useful for many everyday tasks, from tracking work hours to calculating travel time or sleep duration.

Using the Calculator

This tool is simple to use:

  1. Select Format: Choose between the standard 12-hour clock (AM/PM) or the 24-hour military time format.
  2. Enter Start Time: Input the hour, minute, and second when the activity began.
  3. Enter End Time: Input the hour, minute, and second when the activity ended.

The calculator automatically handles cases where the end time is on the next day (e.g., starting at 10 PM and ending at 2 AM).

Common Examples

Start Time End Time Duration
9:00 AM 5:00 PM 8 hours
10:30 PM 6:15 AM 7 hours 45 minutes
1:00 PM 1:45 PM 45 minutes

Calculating Work Hours

If you are using this tool to calculate payroll or shift hours, remember to subtract any unpaid breaks. For example, if the calculator shows a duration of 9 hours but you took a 1-hour unpaid lunch, your billable hours would be 8 hours.