Drywall for a 9 × 9 ft room
With 8 ft ceilings, the walls are 288 ft² and the ceiling 81 ft². Sheet counts include 10% waste; supplies are rules of thumb.
| What you hang | Area | 4×8 sheets | 4×12 sheets | Joint compound | Joint tape |
|---|---|---|---|---|---|
| Walls only | 288 ft² | 10 | 7 | 2.9 gal | 107 ft |
| Walls and ceiling | 369 ft² | 13 | 9 | 3.7 gal | 137 ft |
| Ceiling only | 81 ft² | 3 | 2 | 0.8 gal | 30 ft |
Hanging tips
Hang the ceiling first, then the walls, running sheets horizontally. Stagger the joints, use about one screw per square foot, and tape and mud every seam in three coats. Use moisture-resistant board in bathrooms and fire-rated (5/8 in Type X) in garages and next to furnaces. See the drywall calculator to adjust for your ceilings.
Hauling, studs and screws
A ½ inch 4 × 8 sheet weighs about 55 lb, so the 13 sheets for the walls and ceiling weigh roughly 715 lb (0.36 tons). Most pickups can take a few sheets flat, but a full order is a delivery, or several trips. Carry them on edge, and use a helper.
The walls are 36 ft around, which is about 31 studs at 16 inch centers (the corners add a few). Plan on roughly one screw per square foot, which is 416 screws for this order.
A 9 × 9 room: one foot over a sheet, everywhere
A 9 × 9 room needs 13 sheets of 4 × 8 drywall for the walls and ceiling at an 8 ft height, 10 sheets for the walls alone, or 9 sheets of 4 × 12 for the whole room.
Every wall and both directions of the ceiling are a foot longer than an 8 ft sheet, so with 4 × 8 board each course ends in a one-foot filler and a butt joint. Twelve-foot sheets cut down to 9 ft avoid those joints, and the 3 ft cutoffs fill in above the door and under the windows. Some yards also stock 10 ft sheets, which waste less; ask before you order. In 4 × 8 the board weighs about 715 lb.
Want to change anything else? The calculator above is the full Drywall Calculator: edit any number and the results update instantly.
Tools & materials for this project
Affiliate links As an Amazon Associate we earn from qualifying purchases. These links do not change what you pay.
Frequently asked questions
How many sheets of drywall for a 9x9 room?
13 sheets of 4 × 8 ft for the walls and ceiling with 8 ft ceilings and 10% waste, or 10 for the walls only. With 4 × 12 ft sheets it is 9 for both.
How much joint compound for a 9x9 room?
About 3.7 gallons for the walls and ceiling as a rule of thumb (1 gallon per 100 ft²), so one 4.5 gallon box is enough.
Do I subtract windows and doors for drywall?
Not usually. The cut-outs are offset by the waste allowance, and you need the cutoffs for filling around openings.
Related sizes and guides
Estimates only. Results assume standard materials and simple shapes. Supplier products vary, and the final call on quantity, structure and safety is yours. Check your local code and your supplier's guidance before ordering.