Free tool · for homeowners, remodelers and drywall contractors
Drywall Calculator: Sheets, Joint Compound, Tape and Screws
Add each room’s length, width and ceiling height, include or skip the ceiling, and subtract doors and windows. Get the number of sheets for 4×8, 4×10 or 4×12 sheetrock, plus mud, tape and screws, in one shopping list.
Drywall Calculator
- Room 1440 sq ft
Joint compound uses USG’s guide of about two 4.5-gallon pails of all-purpose compound per 1,000 sq ft. Tape and screw counts are estimates; screw spacing depends on framing and your local code.
How Many Sheets of Drywall Do I Need?
Multiply each room’s perimeter by its ceiling height, add the ceiling area, subtract doors and windows, and add about 10% for waste. Divide by the sheet area: 32 sq ft for 4×8, 40 for 4×10 or 48 for 4×12. A 12×12 room with 8-foot ceilings needs about 18 sheets of 4×8.
Checked against the sources below · How we build and test our calculators
Drywall Sheets by Room Size
8-ft ceilings, ceiling included, one door and one window deducted, 10% waste.
| Room | Area to cover | 4×8 sheets | 4×12 sheets | Joint compound |
|---|---|---|---|---|
| 10 × 10 ft | 388 sq ft | 14 | 9 | 3.5 gal |
| 10 × 12 ft | 440 sq ft | 16 | 11 | 4.0 gal |
| 12 × 12 ft | 496 sq ft | 18 | 12 | 4.5 gal |
| 12 × 14 ft | 552 sq ft | 19 | 13 | 5.0 gal |
| 14 × 16 ft | 672 sq ft | 24 | 16 | 6.0 gal |
| 16 × 20 ft | 864 sq ft | 30 | 20 | 7.8 gal |
How to Estimate Drywall
- Walls: add the length of every wall and multiply by the ceiling height.
- Ceiling: length × width of the room.
- Subtract openings: a 36 × 80 in door is 20 sq ft; measure your windows.
- Add waste: about 10%, more for rooms with many corners.
- Divide by the sheet area and round up.
Your Drywall Shopping List
- Sheets in the size and thickness you chose.
- Joint compound, about 9 gal per 1,000 sq ft for three coats.
- Paper or mesh tape for every joint, plus corner bead for outside corners.
- Drywall screws, 1 1/4 in for 1/2-in board on wood studs is common.
- Sanding sponges, a utility knife and a T-square.
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Questions
How many sheets of drywall do I need?
Add up the wall area (perimeter × ceiling height) and the ceiling area, subtract doors and windows, add about 10% for waste, and divide by the sheet area: 32 sq ft for a 4×8 sheet, 40 for 4×10 and 48 for 4×12. Round up.
How many sheets of drywall for a 12x12 room?
With 8-ft ceilings, the walls are 48 ft × 8 ft = 384 sq ft and the ceiling 144 sq ft. Minus one door and one window (about 32 sq ft) and plus 10% waste, that is about 545 sq ft, or 18 sheets of 4×8.
How much joint compound do I need?
USG says about two 4.5-gallon pails of its UltraLightweight All Purpose joint compound finish 1,000 sq ft of wallboard, so roughly 9 gallons per 1,000 sq ft. Other products and finish levels vary; check the label.
Should I use 4x8 or 4x12 sheets?
Longer sheets mean fewer seams to tape and finish, which saves time and looks better, but they are heavy and hard to carry up stairs. 4×8 sheets are easiest for one person; 4×12 is common for pros.
What thickness of drywall should I use?
Half-inch is standard for interior walls. Five-eighths-inch is used on ceilings with wider framing and where fire-rated (Type X) board is required, such as between a garage and the house. Check your local code.
Does this work for sheetrock?
Yes. Sheetrock is a USG brand name for drywall (gypsum wallboard); the math is the same for any brand.