Duration: 8 hours 30 minutes.
Enter a start time and end time to calculate the elapsed duration. The calculator can handle overnight periods and optionally subtract an unpaid break.
Calculated duration8 hours 30 minutes
Hours and minutes8h 30m
Decimal hours8.50 hours
Total minutes510 minutes
Total seconds30,600 seconds
From 9:00 AM to 5:30 PMSame-day duration
How to Use the Time Duration Calculator
Select the starting time and ending time. Add a break when the elapsed period includes unpaid or excluded time, then chooseCalculate Duration.
When the ending time is earlier than the starting time, the calculator can automatically treat it as occurring on the following day. You may also select the next-day option manually.
Duration: 8 hours.
Less 30 minutes: 8 hours.
Time Duration Formula
Basic formulaDuration = End time − Start time − Break time
Each time is converted into minutes after midnight. The starting value is subtracted from the ending value. When the ending value is earlier, 1,440 minutes are added to represent the following day.
How Overnight Time Is Calculated
A period from 10:00 PM to 6:00 AM crosses midnight. There are two hours from 10:00 PM to midnight and six hours from midnight to 6:00 AM, producing a total duration of eight hours.
Start10:00 PM
2 hoursMidnight6 hours
End6:00 AM
Decimal Hours
Decimal hours express minutes as part of an hour. Divide the minute portion by 60 and add it to the whole hours.
For example, 8 hours 30 minutes becomes 8.5 hours because 30 divided by 60 equals 0.5.
| Hours and minutes | Decimal hours | Total minutes |
|---|---|---|
| 1 hour 15 minutes | 1.25 hours | 75 minutes |
| 2 hours 30 minutes | 2.50 hours | 150 minutes |
| 4 hours 45 minutes | 4.75 hours | 285 minutes |
| 8 hours 30 minutes | 8.50 hours | 510 minutes |
Common Uses
Calculate a shift and subtract lunch or unpaid breaks.
Find the duration between departure and arrival.
Measure time spent studying, reading, or practising.
Calculate the length of meetings, appointments, and activities.
Frequently Asked Questions
How do I calculate the hours between two times?
Subtract the start time from the end time. Convert both times to minutes first when the times include different minute values.
What happens when the end time is earlier?
The calculator treats the ending time as occurring on the next day, producing an overnight duration.
Can the calculator subtract a lunch break?
Yes. Enter the break in hours and minutes. It will be deducted from the elapsed duration.
How are decimal hours calculated?
Divide the remaining minutes by 60 and add that value to the whole-number hours.
Can the duration be longer than 24 hours?
This calculator is designed for two times within the same day or across one midnight. A date-and-time calculator is better for periods spanning several days.