Add hours and minutes

What it's for

Adding 1:45 and 2:30 isn't like adding 1.45 and 2.30: minutes run to sixty, not a hundred, and the carry goes wrong in a moment. Here you type up to three durations in hours:minutes form and out comes the total, both in hours and minutes and in total minutes, which is the number to put in a sheet or a report.

Decimal hours and real hours are not the same thing

This is the mistake that costs money on payslips and in quotes: 1.25 hours isn't 1 hour and 25 minutes, it's 1 hour and 15, because 0.25 of sixty minutes is fifteen. In the same way 1.5 hours is 1:30 and 1.75 is 1:45. The rule for moving between them: minutes divided by 60 give the decimal part, and the decimal part times 60 gives the minutes. A quarter of an hour is 0.25; twenty minutes is 0.333…, already a number that never ends.

When the total goes past twenty-four hours

Here nothing happens: 30:15 stays 30 hours and 15 minutes, because it's a duration and not a time of day. In spreadsheets the opposite happens, and it's the classic trap: a total of hours added with the ordinary time format starts again from zero after 24 and shows 6:15 instead of 30:15. It's solved by giving the cell the format with square brackets, which tells the program not to reset.

Nearby tools

If you have two times and want to know how long passes between them, the page is Difference between two times. For a shift's working hours, with the break to take off, there is Working hours calculator; to convert between units of time Time converter, and for the cost of a job starting from the hours Project cost by hours.