How Much Drywall Do I Need?
Add up all wall and ceiling area, then divide by 32 sq ft for 4×8 sheets or 48 sq ft for 4×12 sheets.
Worked example
A room with 800 sq ft of surface needs 800 ÷ 32 = 25 sheets of 4×8, plus 10–15% for cutouts — about 28 sheets.