How this calculator works
It calculates your total wall area (room perimeter × height), adds 10% for waste and cuts, and divides by the area of one drywall sheet.
Worked example — a 12 ft × 12 ft room, 8 ft walls, 4×8 sheets:
Perimeter 48 × 8 = 384 sq ft × 1.10 = 422 ÷ 32 = 14 sheets.
Perimeter 48 × 8 = 384 sq ft × 1.10 = 422 ÷ 32 = 14 sheets.
Don’t forget the ceiling
This estimate covers walls. If you’re also drywalling the ceiling, add the room’s floor area (length × width) and divide by your sheet size for the extra sheets.
Frequently asked questions
What size drywall sheet should I buy?
4×8 ft sheets are easiest to handle solo; 4×12 ft sheets mean fewer seams but need two people.
How much extra drywall for waste?
About 10% covers offcuts and damaged sheets on a typical room.