Drywall Square Footage Calculator

Standard residential drywall comes in 4×8 sheets (32 sq ft each) and 4×12 sheets (48 sq ft each). Use 4×12 sheets when possible — they're heavier but produce fewer seams, which means less mudding and a smoother finish.

For tall walls (over 8 ft), 4×12 sheets installed horizontally hide the seam at chair-rail height. For ceilings, 4×12 is the standard for professional installs.

You'll need joint compound (mud), tape, and screws beyond the sheets themselves. Plan on roughly 1 gallon of mud per 100 sq ft of finished surface for a level-4 finish, plus drywall tape and 1 lb of screws per 200 sq ft.

For full coverage budget, drywall installation runs $1.50–$3.50 per sq ft installed. Materials alone are usually $0.60–$0.80 per sq ft for the sheets, mud, tape, and screws combined.

Drywall comes in standardized sheet sizes that determine both cost and labor. Larger sheets mean fewer seams to tape — labor cost matters here because taping is the slowest part of any drywall job.

4 × 8 ft sheets (32 sq ft): the home-store default. Easy to handle solo. Best for repair work, small rooms, and DIY installations.

4 × 9 ft sheets (36 sq ft): used in homes with 9 ft ceilings, fits exactly floor to ceiling.

4 × 10 ft sheets (40 sq ft): for 10 ft ceilings or to reduce horizontal seams in standard 8 ft rooms.

4 × 12 ft sheets (48 sq ft): commercial standard. Pros prefer these because fewer sheets means fewer seams, less mud, less sanding. Heavy — needs two people minimum.

4 × 14 ft, 4 × 16 ft: special order. Used in commercial buildings and luxury homes with tall ceilings.

The standard 10% waste factor is right for typical residential work. Increase to 15% if the room has many windows, doors, or angles that require cuts.

For a 12 × 14 ft room with 8 ft ceilings (416 sq ft of wall + 168 sq ft of ceiling = 584 sq ft total): 4×8 sheets = 584 ÷ 32 = 18.25, round up to 20 sheets with waste. 4×12 sheets = 584 ÷ 48 = 12.2, round up to 14 sheets.

Skip the floor when calculating drywall (floors don't get drywall). Include the ceiling if you're drywalling the whole room.

Don't subtract for doors and windows — you'll need full sheets to cut the openings out of, and the off-cuts get used elsewhere.

Drywall sheets are just the start. A full installation needs supporting materials, priced per square foot or per sheet:

Joint compound (mud): 1 gallon covers about 100 sq ft of taped seams. A 5-gallon bucket ($15-25) handles roughly 500 sq ft of finished wall.

Drywall tape: $4-8 per 250-foot roll. About 1 linear foot of tape per sq ft of wall.

Drywall screws: 1 lb covers about 320 sq ft (screws every 12 inches along studs, every 16 inches on field). Buy 1 lb per 300 sq ft.

Corner bead (for outside corners): $3-6 per 8 ft length. Calculate by linear feet of outside corner in the room.

Sandpaper, primer, and final paint are extra. Total cost for full materials (not labor) on a 500 sq ft drywall job: $200-400.