Calculate sheets needed for walls & ceilings
This calculator estimates the number of drywall sheets needed for your walls and ceilings, accounting for doors, windows, and waste.
Standard door: Assumed as 21 sq ft (3' × 7')
Standard window: Assumed as 15 sq ft (3' × 5')
Sheet sizes: 4'×8' sheets are standard and easier to handle. 4'×12' sheets reduce seams but are harder to install and typically used for ceilings or tall walls.
Waste factor: Always add extra for cutting errors, damaged sheets, and odd angles. 10% is minimum, 15-20% for complex rooms with many corners or angles.
How to use: Measure total wall length (perimeter), enter height, count doors and windows, add ceiling area if needed. The calculator includes waste automatically.