Time Duration Calculator

Calculate elapsed duration between two clock times, including an overnight rollover.

How this calculator works

Enter the values for start time, end time. The result applies the displayed method and rounds only for presentation.

Formula / method

Duration = end time − start time, adding 24 hours when the end is earlier.

Worked example

Worked example: Start time = 09:00; End time = 17:30.

Assumptions and limitations

The inputs use the units shown and the displayed time duration calculator method applies to the situation being estimated.

This time duration calculator uses the stated formula and supplied units; unusual inputs, local rules or professional context can change the interpretation.