How Many Sheets of Drywall for a 12×12 Room?
October 22, 2026 · 6 min read
Sheet counts for a 12×12 room with 8 or 9 ft walls, with and without the ceiling, in 4×8, 4×10 and 4×12 sheets, plus the screws, mud and tape you need.
The quick answer
A 12 × 12 ft room with 8 ft ceilings needs 17 sheets of 4×8 drywall to cover the walls and the ceiling, allowing for one door, one window and 10% waste. For the walls alone, it's 12 sheets. With longer 4×12 sheets, the same room takes 12 sheets in total.
Different ceiling height, more windows or a closet? Enter your room in our drywall calculator to get the sheet count, screws, joint compound and tape in one go.
How to work it out
- Wall area. Perimeter × wall height: (12 + 12 + 12 + 12) × 8 = 384 sq ft.
- Ceiling area. Length × width: 12 × 12 = 144 sq ft.
- Subtract openings. A standard door is about 3 × 7 ft (21 sq ft) and a typical window about 3 × 5 ft (15 sq ft), so 36 sq ft comes off. That leaves 384 − 36 + 144 = 492 sq ft to cover.
- Divide by the sheet size and add waste. A 4×8 sheet covers 32 sq ft: 492 ÷ 32 = 15.4 sheets. Add 10% for cutouts and offcuts: 15.4 × 1.10 = 16.9, so buy 17 sheets.
Don't subtract openings too eagerly. The pieces you cut out for a window are rarely reusable, which is why the 10% waste allowance matters. For rooms with lots of corners, soffits or a sloped ceiling, use 15%: that takes this room to 18 sheets.
Sheets for a 12×12 room by sheet size and wall height
All counts assume one door and one window (36 sq ft of openings) and 10% waste, rounded up to whole sheets:
| Wall height | What you're covering | 4×8 sheets | 4×10 sheets | 4×12 sheets |
|---|---|---|---|---|
| 8 ft | Walls only | 12 | 10 | 8 |
| 8 ft | Walls + ceiling | 17 | 14 | 12 |
| 9 ft | Walls only | 14 | 11 | 10 |
| 9 ft | Walls + ceiling | 19 | 15 | 13 |
Longer sheets mean fewer sheets and, more importantly, fewer butt joints, which are the hardest joints to tape flat. The trade-off is weight and handling: 12 ft sheets are heavy, awkward to get through doorways and up stairs, and usually need two people. For a DIY job in a finished house, 4×8 sheets are often the practical choice. Run your own numbers for any sheet size in the drywall sheet calculator.
Other room sizes
Walls and ceiling, 8 ft walls, one door and one window, 4×8 sheets, 10% waste:
| Room | Area to cover | 4×8 sheets |
|---|---|---|
| 10 × 10 ft | 384 sq ft | 14 |
| 12 × 12 ft | 492 sq ft | 17 |
| 12 × 14 ft | 548 sq ft | 19 |
| 14 × 16 ft | 668 sq ft | 23 |
For an L-shaped room, or one with a closet or alcove, add up the floor area section by section in our square footage calculator, then measure the wall lengths around the whole perimeter.
Screws, joint compound and tape for a 12×12 room
For the walls and ceiling (492 sq ft, 17 sheets of 4×8), plan on:
- About 550 drywall screws. Under the International Residential Code (Table R702.3.5), screws go every 16 inches on walls framed 16 inches on center, and every 12 inches on ceilings, as summarized in this 2021 IRC drywall inspection checklist. That works out to roughly 28 screws per sheet on walls and more on ceilings, or about 32 per sheet on average.
- About 4½ gallons of joint compound. USG says to expect roughly two 4.5-gallon pails of all-purpose compound per 1,000 sq ft of drywall, so about one pail for this room. Keep a small extra box for touch-ups and sanding repairs.
- About 180 ft of joint tape, plus metal or paper-faced corner bead for any outside corners, such as window returns.
The drywall calculator shows all three for your room, based on these same rates.
Which drywall to buy
- Walls: standard ½-inch drywall is the usual choice for walls in a house.
- Ceilings: use ½-inch sag-resistant ceiling board or ⅝-inch board, especially where the ceiling joists are 24 inches apart.
- Bathrooms: moisture-resistant board is fine for walls outside the shower. Behind tile in tub and shower areas, the IRC calls for cement, fiber-cement or glass-mat backer board instead (R702.4.2).
- Garages: if there are living spaces above the garage, the ceiling needs ⅝-inch Type X fire-rated board (R302.6). Check with your building department before you start.
Hanging tips
- Do the ceiling first. Then hang the top row of wall sheets tight up against it, so the wall board helps support the ceiling edges.
- Land every end on framing. Butt ends must break over a stud or joist, not float in between.
- Stagger the joints and keep them away from the corners of doors and windows, where cracks like to start.
- Plan the paint at the same time. New drywall needs a coat of primer before the finish coats. Our paint calculator works out how much you need for the same room.
Sources & further reading
- How much joint compound do I need? (FAQ) — USG
- 2021 I-Code Residential Inspection Checklist: Drywall — Town of Cave Creek, Arizona
- International Residential Code 2021, Chapter 7: Wall Covering (R702) — International Code Council