Converting decimal number of hours into time

Posted on

QUESTION :

I need to convert number of hours, such as 156.90 to 156:54 in excel 2003.

All of the conversions I found did this incorrectly. The number of hours shouldn’t be changed, only the decimal.

ANSWER :

=TRUNC(A1)&":"&REPT("0",2-LEN(ROUND(60*(A1-TRUNC(A1)),0)))&ROUND(60*(A1-TRUNC(A1)),0)

Where A1 is the decimal value.

Be aware that dates and times in Excel are stored internally as an amount of days. You can use this fact to simplify conversions of time amounts.

If you have an amount of hours in A1 you can calculate an amount of days using =A1/24 then display it as hours and minutes using the custom number format [h]:mm. Follow these steps:

  1. In the desired cell, enter the formula =A1/24
  2. Right click on the cell and choose Format Cells.
  3. On the Number tab, choose the Custom category, then type in [h]:mm

For more information about custom formats, see Create or delete a custom number format and Number format codes (look at the last section “Displaying hours, minutes, and seconds”). The brackets [ ] in the format code tell Excel to treat the amount as a duration and not a time of day. If you leave them off 25 hours is displayed as 1:00 because Excel interprets it as “1:00 AM of the next day”.

You can use this kind of method to convert other amounts of time (amounts of seconds, minutes, or hours) into display formats like [h]:mm, [m]:ss, [h]:mm:ss or so on. Just use a formula to convert the amount to days, then use a custom number format to display the way you want. For example, if A1 is an amount of seconds, you can use =A1/24/60/60 with format [m]:ss.0 to get minutes, seconds, and tenths of seconds.

I find this method easier to remember and re-create as needed. The disadvantage is if other people need to edit your spreadsheet and they change the number format or copy and Paste Special, Values to a new location, the values no longer make sense.

The easiest way to do this is to use @Bavi_H ‘s method, but instead wrap the formula in a TEXT() function specifying the format.

=TEXT(A1/24,"[h]:mm")

That way you don’t need to rely on setting and maintaining number formats for the cell. And even though the value is stored as text, it can still be used in calculations (e.g. =MINUTES(B1) will return 54, and =TEXT(2*B1,"[h]:mm") will return 313:48).

Leave a Reply

Your email address will not be published. Required fields are marked *