Drywall Sheets Calculator
Calculate drywall sheets for any room from wall and ceiling dimensions, door and window cutouts, and sheet size.
Includes 10% waste and joint compound estimate.
Drywall (sheetrock) is the standard wall and ceiling material for interior construction. Estimating the right amount avoids waste and extra trips to the store.
Basic formula:
Sheets Needed = (Total Wall Area - Openings) / Sheet Area
Standard drywall sheet sizes:
| Size | Area | Common Use |
|---|---|---|
| 4 x 8 feet (1.2 x 2.4 m) | 32 sq ft (3.0 sq m) | Standard walls |
| 4 x 10 feet (1.2 x 3.0 m) | 40 sq ft (3.7 sq m) | Taller walls |
| 4 x 12 feet (1.2 x 3.7 m) | 48 sq ft (4.5 sq m) | Fewer seams |
Calculating wall area:
Wall Area = Perimeter x Ceiling Height
Perimeter = 2 x (Room Length + Room Width)
Subtract for openings:
- Standard door: ~21 sq ft (2.0 sq m)
- Standard window: ~15 sq ft (1.4 sq m)
Waste factor: Always add 10-15% for cuts, mistakes, and odd angles. Rooms with many corners or angles need more waste allowance.
Drywall thickness options:
- 1/4 inch (6.4 mm): Curved walls only
- 3/8 inch (9.5 mm): Overlay on existing walls
- 1/2 inch (12.7 mm): Standard for walls
- 5/8 inch (15.9 mm): Ceilings and fire-rated applications
Joint compound and tape: Budget about 1 box of compound and 1 roll of tape per 10 sheets.