How do i get a square size for my stair walls?

Question

could i do it by puting it into 2 sections - ie top - width x height

and bottom length x height.

Answer 1

If you are painting, just measure the length and width of the ceiling which will give you the area there.  Then measure the length and height of the side wall(s).  Add each dimension all together to get your total.  If you are paneling add 10% of the total for waste in cutting 4x8 sheets.

Answer 2

a square size what for your stair walls?