How to retrive OVERALL flat blank AREA IN sw 2008

What I mean

When anybody creates sheet metal part SW gives us flat blank automaically but in order to do it You need to cakculate falt blank area in order to let manufacturing know how much material they need to do it and You need to enter it in the manugacturing systen in order to purcgasing know how much material they need to order ETC

it should be simple for SW to give us link to calculate overall - for any shape - flat blank area like they let us to link it to material,item number,description

Does anybody know how to do it w/o using calculator

We usually take x, y add 1/8 to each dimension and calculate area.

Maybe somebody who knows API know how to link it, please