Drywall calculator
Sheets for walls, with an option to include the ceiling — plus how much joint compound and how many screws to grab.
Room details
How this is calculated
Wall area comes from the room's perimeter times height: 2 × (length + width) × height. If you're also hanging the ceiling, its area (length × width) gets added in. That total is divided by your sheet size, then increased by 10% to cover waste from cuts around outlets, corners, and mistakes — a standard margin for a simple rectangular room. Joint compound is estimated at roughly one 5-gallon bucket per 250–300 sq ft, and screws at about 1 lb per 25 sq ft of drywall.
4×8 or 4×12 sheets — which is better?
4×12 sheets mean fewer seams to tape and mud, which is faster on long walls, but they're heavier and harder to maneuver alone. Most DIY jobs use 4×8.
Do I need a bigger waste margin for a room with lots of corners?
Yes — an irregularly shaped room or one with many closets and alcoves can push waste closer to 15%. Add a sheet or two beyond this calculator's result if your room isn't a simple rectangle.
What thickness of drywall should I use?
1/2" is standard for most interior walls, 5/8" for ceilings and fire-rated walls (like garage-to-house walls), and 1/4"–3/8" for curved surfaces or re-covering existing walls.
Once you know how much to order
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1/2" drywall sheet, 4×8
Standard interior wall thickness, matches the default above.
View on Home DepotDrywall screws, 5 lb box
1-1/4" coarse thread, standard for wood studs.
View on Home Depot