I would highly recommend you not do this.

Use an input cell then use a formula to do the calculation in another cell.

A1 = input cell
B1 = formula

=IF(COUNT(A1),A1*0.585,"")

If you do it the way you want and you make a mistake how will you know? You
won't unless it's very obvious.


--
Biff
Microsoft Excel MVP


"Mikeebabe" wrote in message
...
I'm trying to format a cell in a way where the number I input will
automatically be multiplied by a number predetermined by me.
ie: I format cell a1 so it's contents is multiplied by .585
when I input the number 10 in cell a1 it will display as 5.85