Date & Time
Time Duration Calculator
Calculate the exact duration between two times in hours, minutes, and seconds. Supports overnight ranges that cross midnight.
Time range
Duration
8:30:00
8 hours, 30 minutes, 0 seconds.
Total seconds
30,600
Total minutes
510
Total hours
8.5
Frequently Asked Questions about the Time Duration Calculator
How do I calculate the duration between two times?
Enter a start time and an end time. The calculator shows the gap as H:MM:SS, spells it out in hours, minutes, and seconds, and also gives you the total seconds, total minutes, and total hours.
What does the crosses midnight option do?
Tick it when your end time lands on the next day, like a shift from 10:00 PM to 6:00 AM. When the end time is earlier in the clock than the start, the calculator adds 24 hours so you get 8 hours instead of a negative result. If the end time is already later than the start, the box has no effect.
Why is nothing showing when my end time is earlier than my start time?
An end time earlier than the start gives a negative duration, so the calculator waits for valid input instead of showing a wrong number. Tick the crosses midnight box, or swap the two times.
Can I include seconds?
Yes. The time fields have a seconds slot, so you can enter values like 9:00:30 AM and measure a range down to the second.
What is the difference between total minutes and the H:MM:SS result?
H:MM:SS breaks the duration into hours, minutes, and seconds, so 2:30:00 means 2 hours and 30 minutes. Total minutes states the same span as one number, 150 in that case, which is easier to drop into billing or a spreadsheet.