Drywall Square Foot
Calculator — Sheet Estimator

Calculate total wall area in square feet, subtract window and door openings, then divide by the sheet size. A standard 4×8 sheet covers 32 sq ft. For a room with 480 sq ft of wall area minus 60 sq ft of openings, you need 420 ÷ 32 = about 14 sheets, plus 10% for waste.

Measure the perimeter of the room and multiply by the ceiling height to get total wall area. Subtract the area of all windows and doors. A 12×14 room with 8-ft ceilings has a perimeter of 52 ft and a total wall area of 416 sq ft before subtracting openings.

The most common drywall sheet is 4 feet × 8 feet (32 sq ft). Other sizes include 4×10 (40 sq ft), 4×12 (48 sq ft), and 4×14 (56 sq ft). Longer sheets reduce the number of seams on taller walls.

Yes, subtract the area of windows and doors from total wall area before calculating sheet count. A standard door opening is about 21 sq ft (3 ft × 7 ft) and a typical window is about 12 sq ft (3 ft × 4 ft).

Add 10% to 15% extra for waste, cuts, and mistakes. For rooms with many openings or corners, use 15%. For simple rectangular walls, 10% is usually sufficient.

Standard 1/2-inch drywall costs about $0.40 to $0.65 per square foot for materials only. Installation labor adds $1.00 to $2.50 per square foot depending on complexity. Enter your price per square foot in the calculator to estimate total cost.