How Many Sheets of Drywall Do I Need?
Drywall count is wall and ceiling area ÷ the area of one sheet, plus waste. A standard 4×8 sheet covers 32 ft². Use the Drywall Calculator to total sheets for any room.
Ready to run the numbers? Use our Drywall Calculator or the Square Footage Calculator to get an instant material estimate.
Measure wall and ceiling area
For each wall, multiply height × width in feet and add the walls together. If you are drywalling the ceiling, add the room’s length × width as a separate area. Then subtract openings you will not cover — doors (about 21 ft² each) and windows (about 15 ft² each).
A 12×12 ft room with 8 ft walls: 4 × (12 × 8) = 384 ft², minus one door (21) and two windows (30) = 333 ft² of wall. Add a 144 ft² ceiling for 477 ft² total.
Standard sheet sizes
- 4×8 ft sheet — 32 ft², the most common for DIY.
- 4×10 ft sheet — 40 ft², fewer joints on 9–10 ft walls.
- 4×12 ft sheet — 48 ft², for high ceilings; harder to handle alone.
- 1/2 in for walls and ceilings; 5/8 in fire-rated for garages and between house and garage.
Waste and sheet count
Divide total area by the area of one sheet and round up. Add 10% waste for cuts, breakage and odd cavities around outlets and corners. You will almost always cut sheets to fit, so a little extra is cheaper than running one sheet short.
Source: 4×8 sheet = 32 ft²; 4×10 = 40 ft²; 4×12 = 48 ft². Round up to the next whole sheet.
333 ft² of wall with 10% waste = 366 ft² ÷ 32 ft² per 4×8 sheet = 11.4 → 12 sheets.
Buying and hanging tips
- Budget for joint compound, tape, corner beads and screws separately.
- A drywall lift is worth renting for ceilings — it saves your back and your walls.
- Hang ceilings first, then walls, so wall sheets support the ceiling edges.
- Buy one or two extra sheets; unopened sheets are usually returnable.
Frequently asked questions
How many sheets of drywall do I need for a 12×12 room?
A 12×12 ft room with 8 ft walls has about 333 ft² of wall after one door and two windows. With 10% waste and 4×8 sheets (32 ft²) you need about 12 sheets. Add 5 more for the ceiling.
How many square feet is a 4×8 sheet of drywall?
A 4×8 ft sheet covers 32 ft². A 4×10 covers 40 ft² and a 4×12 covers 48 ft². Divide your total wall and ceiling area by the sheet area to get the count.
How much waste should I add for drywall?
About 10% for cuts, breakage and fitting around outlets and corners. Odd-shaped rooms or first-time installers may want 15%.
Calculators for this guide
Put these numbers to work with the free calculators referenced above.