Time Duration Calculator
Enter a start time and an end time to get the duration in hours and minutes plus decimal hours. Handles overnight shifts automatically and can deduct unpaid breaks.
Duration: ?
How duration is calculated
Both times are converted to minutes since midnight, then subtracted. If the end is earlier than the start, the calculator adds 24 hours — that is what an overnight shift means. A 10:00 PM to 6:00 AM shift is exactly 8 hours.
Frequently asked questions
How do I calculate duration in Excel?
Subtract the two cells and format the result as time, or multiply by 24 for decimals: =(B2−A2)*24. Negative results mean the shift crossed midnight — add 1 to the result.
How many hours is 3:30 plus 40 minutes?
3:30 + 0:40 = 4:10 — four hours ten minutes, or about 4.17 decimal hours.