Area calculations assume rectangular rooms. For L-shaped or irregular rooms, break them into rectangles and sum the areas. Material estimates follow standard manufacturer coverage rates.

Drywall Calculator by Room Dimensions

Enter room length, width, and ceiling height. The calculator finds total wall and ceiling area, then estimates sheets, compound, tape, and screws.

Room Dimensions

Total area
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Drywall sheets
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Joint compound
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4.5-gal pails
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Joint tape
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Tape rolls (500 ft)
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Drywall screws
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Screw boxes (1 lb)
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How room-size drywall estimates work

The calculator computes wall area as perimeter × ceiling height, where perimeter = 2 × (length + width). Ceiling area = length × width. Doors and windows are subtracted using typical rough-opening sizes (15 sq ft per door, 9 sq ft per standard window). Total area is then fed into the same sheet-count engine used by the main calculator.

For rooms with built-ins, soffits, or irregular ceilings, add or subtract those areas manually and enter the adjusted total on the main drywall calculator.

Frequently Asked Questions

How do I calculate drywall for a 12×12 room with 8-ft ceilings?

Perimeter = (12+12) × 2 = 48 ft. Wall area = 48 × 8 = 384 sq ft. Ceiling = 12 × 12 = 144 sq ft. Total = 528 sq ft. With 4×8 sheets and 10% waste: ⌈(528/32) × 1.10⌉ = ⌈18.15⌉ = 19 sheets.

Should I subtract door and window openings?

For a general estimate you can include them — the extra material from unsubstracted openings often offsets cuts and waste. For a tighter estimate, subtract about 15 sq ft per door and 9 sq ft per standard window, then add your waste factor.

Do I include the ceiling in my drywall estimate?

Yes, unless you plan to leave it unfinished (like a garage). The ceiling is typically included in total drywall area. The calculator uses a blended screw rate for walls+ceiling (1.25 screws/sq ft); select "ceiling only" if you are finishing just the ceiling.

What if my room is not a simple rectangle?

Break L-shaped or irregular rooms into rectangles. Measure each section separately, calculate the area of each rectangle, and add them together before entering the total in the calculator.

How many sheets for a 10×10 room?

Walls: perimeter 40 ft × 8 ft ceiling = 320 sq ft. Ceiling: 100 sq ft. Total: 420 sq ft. With 4×8 sheets and 10% waste: ⌈(420/32) × 1.10⌉ = ⌈14.44⌉ = 15 sheets.

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