Just by entering the length, width and height of a room, the Construction Master Pro can figure out the area of the walls and the walls plus the ceiling. *For the walls only, push CONV, then push HEIGHT until WALL displays. If you want to include the ceiling area, push HEIGHT one more time until ROOM is displayed. Once you have the area figured out push CONV then HEIGHT. Repeated pushes of HEIGHT will show you how many boards you need for the different common sizes. #newbuildhome #mathneverlies