CalcLoft
Work & Time

Time Duration Calculator

Result
5h 30m
5.5 hours

Enter a start time and an end time and this calculator returns the elapsed duration in hours and minutes and as a decimal. From 9:15 AM to 2:45 PM is 5 hours 30 minutes, or 5.5 hours. If the end time is earlier than the start, tick the overnight option to count the span across midnight instead of treating it as zero.

The formula

duration = end − start (add 24h if the span crosses midnight)

Convert both times to minutes since midnight and subtract. A negative result means the period wrapped past midnight, so add 24 hours (1,440 minutes).

How to use it

  1. 1

    Enter start and end times

    Type the two times in 1:15 PM or 24-hour 13:15 form. The order is start then end.

  2. 2

    Tick overnight if needed

    If the period runs past midnight — like 11:00 PM to 2:00 AM — enable overnight so the calculator adds the extra day.

  3. 3

    Read the elapsed time

    You get the duration as hours and minutes and as a decimal, ready to drop into a timesheet or schedule.

Frequently asked questions

How is this different from the hours calculator?
Duration measures plain elapsed time between two clock times with no break handling. The hours calculator subtracts an unpaid break for payroll, which this one doesn't.
Does it cross midnight?
Yes — enable the overnight option and a span like 10:30 PM to 6:00 AM returns 7 hours 30 minutes instead of an invalid result.
Can I get the result in minutes?
Multiply the decimal hours by 60, or read the minutes shown in the hours-and-minutes figure. 2.25 hours is 135 minutes.

Related calculators

Part of Work & Time Calculators. Last updated 2026-06-14.