It's easier than you think Gary, since 1 is one day in Excel which is 24
hours, so one hour is 1/24

just divide by 24

=A1/24

where A1 holds 0.5

then the important thing is to format the cell with the formula as either
hh:mm:ss or [hh}mm:ss  (the latter allows for displaying more than 24 hours)

Same goes for the other way around if you have Excel time format and wants
to calculate  an amount using an hourly rate

=A1*24*hourly_rate

here it is equally important to format result as currency or number

Assuming your decimal time is in column A and begins with A1,
custom format column B as [h]:mm
and then in B1 enter  =A1/24

.5 should then show as 0:30,  1.75 as 1:45, and so on.

If you want your  time to show as 0h 30m and 1h 45m instead,
then custom format  column B as [h]"h"" "mm"m"

--
Alan

It depends on what format you want the results. If you simply want .5 to
become 30 then multiply by 60.

However, if you want .5 to be formatted in minutes then it is .5 divided by
24 and then you have to format the cell to minutes.

To apply a multiplication or division to multiple cells, enter a value in
any spare cell and copy it. Select the range where you want it applied and
Paste Special and select Multiply or Divide etc. This operation ignores text
in the paste to selection.

Tip: Make a backup of your workbook before applying these operations.

Regards,

OssieMac