Drywall for a 12 × 15 ft room
With 8 ft ceilings, the walls are 432 ft² and the ceiling 180 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 | 432 ft² | 15 | 10 | 4.3 gal | 160 ft |
| Walls and ceiling | 612 ft² | 22 | 15 | 6.1 gal | 226 ft |
| Ceiling only | 180 ft² | 7 | 5 | 1.8 gal | 67 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 22 sheets for the walls and ceiling weigh roughly 1,210 lb (0.61 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 54 ft around, which is about 45 studs at 16 inch centers (the corners add a few). Plan on roughly one screw per square foot, which is 704 screws for this order.
A 12 × 15 room: the last sheet is nearly all spare
A 12 × 15 room with 8 ft ceilings takes 22 sheets of 4 × 8 drywall for the walls and ceiling, or 15 for the walls only. The area with waste works out only a little over 21 sheets, so the final sheet is close to a full spare.
Keep that spare; a living room this size usually has enough outlets, vents and openings to use it. The two 12 ft walls suit 4 × 12 sheets hung sideways with no butt joint, while the 15 ft walls need a joint whichever size you buy (the whole room in 4 × 12 is 15 sheets). The 180 sq ft ceiling is about 5.6 sheets of area, and the full order is around 1,210 lb, so have it delivered.
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Tools & materials for this project
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Frequently asked questions
How many sheets of drywall for a 12x15 room?
22 sheets of 4 × 8 ft for the walls and ceiling with 8 ft ceilings and 10% waste, or 15 for the walls only. With 4 × 12 ft sheets it is 15 for both.
How much joint compound for a 12x15 room?
About 6.1 gallons for the walls and ceiling as a rule of thumb (1 gallon per 100 ft²), so buy 2 boxes of 4.5 gallons.
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.