Drywall Calculator
Estimate how many drywall sheets you need for a room, with or without the ceiling. You also get an approximate count of screws and joint tape.
- Area to cover
- 384 sq ft
- Screws (approx.)
- 448 screws
- Joint tape (approx.)
- 170 ft
How this calculator works
Wall area is the room perimeter, 2 × (length + width), multiplied by the wall height. The ceiling area (length × width) is added if you include it.
The area plus an extra percentage for waste is divided by the area of one sheet and rounded up. Openings for doors and windows are not subtracted, because the cut-outs are rarely reusable.
Screws are estimated at about one per square foot of drywall, and joint tape at roughly 370 feet per 1,000 square feet.
Example: a 12 × 12 ft room with 8 ft walls
- Wall area: 2 × (12 + 12) × 8 = 384 sq ft.
- Add 10% for waste: 422.4 sq ft.
- Sheets of 4 × 8 ft (32 sq ft): 422.4 ÷ 32 = 13.2, so 14 sheets.
- Including the ceiling (144 sq ft): 528 × 1.10 ÷ 32 = 18.2, so 19 sheets.
Quick reference
| Room size | Wall area | Sheets |
|---|---|---|
| 10 × 10 ft | 320 sq ft | 11 |
| 12 × 12 ft | 384 sq ft | 14 |
| 12 × 16 ft | 448 sq ft | 16 |
| 15 × 20 ft | 560 sq ft | 20 |
Tips before you buy
- Longer sheets (4 × 12) mean fewer joints to tape and finish, but they are heavy and harder to carry.
- Use moisture-resistant board in bathrooms and fire-rated board where your local code requires it.
- Hang ceiling sheets before the walls so the wall sheets support the ceiling edges.
Frequently asked questions
How many sheets of drywall do I need for a 12 × 12 room?
For 8 ft walls you need about 14 sheets of 4 × 8 drywall with 10% extra, or 19 sheets if you also cover the ceiling.
Should I subtract doors and windows?
Most installers do not. The pieces cut out for openings are usually too small or awkwardly shaped to reuse, so they serve as your waste allowance.
How many screws per sheet of drywall?
About 32 screws for a 4 × 8 sheet on walls with studs 16 inches apart. Ceilings need slightly more.
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Last updated October 25, 2026