Drywall Calculator: Sheets, Screws and Mud
Work out how many sheets of drywall a project needs. Enter a known wall area, or a room's length, width and height, optionally add the ceiling, then read off sheets, screws and joint compound.
How to estimate drywall for a room
- Enter the room length, width and wall height, or a known wall area.
- Tick the ceiling if you are hanging it, and pick your sheet size and waste.
- Read off the sheets, screws and gallons of joint compound to buy.
Examples
12 by 12 ft room, 8 ft walls, with ceiling
L 12, W 12, height 8, ceiling on, 4x8 sheets, 10% waste
528 sq ft, 19 sheets, 608 screws, 3 gallons of mud
Frequently asked questions
What size drywall sheet should I use?
The common sheet is 4 by 8 feet, which covers 32 square feet. Sheets 4 by 12 feet cover 48 square feet and mean fewer butt joints on long walls, but they are heavier and harder to handle alone.
How much waste should I add?
Around 10 percent is typical to cover cuts around doors, windows and outlets, plus the odd damaged sheet. Rooms with many openings or angles can run higher, so bump it up if your layout is complex.
How many screws per sheet of drywall?
Plan on about 32 screws per 4 by 8 sheet, fastening into studs every 12 inches in the field and 8 inches on the edges. The calculator uses 32 per sheet so you buy enough.
How much joint compound will I need?
A rough rule is half a gallon of ready mixed compound per 100 square feet of drywall for taping and three coats. The estimate rounds up so you do not run short mid coat.
Does this subtract doors and windows?
No. The estimate uses the full wall area so you always have enough, and the waste percentage absorbs the small offcuts around openings. For large openings, you can lower the wall area by hand.
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