At first format A3 as percent.
(Go to Format, Format cells and select "percent" from drop down menu).

Then for A3,
enter the formula,
=(A2-A1)/A1

Tina

"pol" wrote:

Hi all,

Please help to write a formula for the following case

A1 cell conatin cost value 500

A2 Cell contaain sales value 700

In A3 cell I have to find out the % of profit

With thanks

Polachan