How Do I Change Hours & Minutes Into a Decimal Number in Excel?. ... Using a quick equation, you can convert an existing set of time data written in "hh:mm" format to hours in decimal format.

If you've already entered time into a cell, you can easily reformat it to include hours, minutes and seconds using the Format Cells dialog. Insert Time Formula Select the cell you want to convert ...

Clock displays divided the hour into halves, thirds, quarters and sometimes even 12 parts, but never by 60. In fact, the hour was not commonly understood to be the duration of 60 minutes.