I am trying to calculate the difference month on month of sales figures whether up or down any ideas how I can do it with excell

Steve -- Do you mean comparing Oct 08 to Oct 07? A B C 1 Oct 07 Oct 08 % diff 2 $10000 $11000 =(B2-A2)/A2 formatting column C as % would show the difference as a percentage of the 2007 month. HTH

Calculating the difference between two numbers is called subtraction. You do it with this kind of formula in Excel: =a2-a1 Regards, Fred.