Sheets from wall area
A 4×8 drywall sheet covers 32 square feet. The calculator takes wall perimeter × height (minus openings), adds the ceiling if you include it, and converts to sheets with the standard <strong>10% waste for cuts, boot holes and the sheet that cracks</strong> on install day.
Seams decide the sheet count
Pros hang sheets horizontally (perpendicular to studs) on 8-foot walls — fewer seams, stronger wall, and the standard 12-foot sheets on taller walls reduce joints further. If your wall height or length fits 12-foot sheets without waste, buy 12-footers: fewer seams to tape means fewer future cracks, even at the higher sheet price.