Formula & assumptions
Decimal hours = hours + minutes ÷ 60
Decimal hours express part of an hour as a base-10 fraction, while the minutes part of a duration is base 60. This tool keeps those representations separate. Converting back rounds to the nearest whole minute and carries 60 minutes into the next hour. It is a duration converter rather than a time-of-day parser.
Worked example
EXAMPLE
7:30 converts to 7 + 30/60 = 7.5 hours. In the other direction, 7.30 decimal hours converts to 7:18. A duration of 27:15 is 27.25 hours.
How to use this calculator
- Choose the conversion direction.
- Enter either an hours:minutes duration or a decimal-hour amount; the unused field is hidden.
- Copy the result in the format expected by your timesheet.
Frequently asked questions
Can I enter more than 24 hours?
Yes. 40:30 is a duration of 40.5 hours. The time does not wrap around at midnight.
How are decimal hours rounded?
Decimal results show up to six places. Conversion to hours and minutes rounds to the nearest minute.
Can the minutes part be 90?
No. Write 1:30 rather than 0:90 so that the input has a consistent hours:minutes format.