Works for 4×8, 4×10 and 4×12 sheets. Larger sheets cut down on seams in rooms with long walls.
How to use the drywall calculator
- Measure the room length, width and wall height.
- Choose whether to include the ceiling.
- Enter the number of doors and windows.
- Pick your sheet size and keep about 10% extra for cuts and mistakes.
The formula
Area: 2 × (length + width) × height − openings (+ ceiling area).
Sheets: area × (1 + waste %) ÷ sheet area (32 sq ft for 4×8), rounded up.
Drywall needed for common rooms (8 ft walls with ceiling, 1 door, 2 windows, 4×8 sheets, 10% extra)
| Room size | Area | 4×8 sheets |
|---|---|---|
| 10 × 10 ft | 370 sq ft | 13 |
| 10 × 12 ft | 422 sq ft | 15 |
| 12 × 12 ft | 478 sq ft | 17 |
| 12 × 14 ft | 534 sq ft | 19 |
| 15 × 20 ft | 810 sq ft | 28 |
Frequently asked questions
How many sheets of drywall for a 12×12 room?
With 8 ft walls, the ceiling, one door and two windows, about 17 sheets of 4×8 drywall including 10% extra.
How many screws per sheet of drywall?
About 28 to 32 screws for a 4×8 sheet on walls, with slightly more on ceilings. One pound of 1-1/4 inch screws is roughly 300 screws.
What thickness of drywall should I use?
1/2 inch is standard for walls. 5/8 inch is common for ceilings and is often required for fire-rated walls, such as between a garage and the house.
Should drywall be hung vertically or horizontally?
Horizontal hanging is common on walls 8 ft tall or more because it usually means fewer seams, and the seams sit at a comfortable height for finishing.
Results are estimates for planning and budgeting. Always confirm measurements and product coverage before you buy, and follow local building codes.