How to use it
- Enter room length, width and wall height.
- Choose whether to include the ceiling.
- Enter the number of doors and windows.
- Pick the sheet size.
The formula
Wall area = perimeter × height − openings
Sheets = (walls + ceiling) ÷ sheet area × (1 + waste)
Worked example
| Room length | 14 ft |
| Room width | 12 ft |
| Wall height | 8 ft |
| Include ceiling | Yes |
| Doors + windows | 2 |
| Sheet size | 4 × 8 ft |
| Waste | 10 % |
Result
| Drywall sheets | 20 |
| Total area | 554 ft² |
| Joint compound (≈1 gal per 100 ft²) | 5.5 gal |
| Joint tape (≈370 ft per 1,000 ft²) | 206 ft |
| Screws (≈32 per sheet) | 640 |
Tips before you order
- Use 12 ft sheets on long walls to reduce butt joints.
- Use ⅝ in Type X board where code requires fire resistance, such as garage walls next to living space.
Questions
How many sheets of drywall for a 12×12 room?
With 8 ft walls and a ceiling, about 18 sheets of 4×8 including 10% waste and two openings.