Project Parameters
Length of the room in feet.
Width of the room in feet.
Floor to ceiling framing height.
Instant Estimate
Selected Sheet Format
Joint Compound Mud (4.5 gal buckets)
Standard all-purpose or lightweight taping mud.
Drywall Screws (1-1/4 in coarse)
Approx. 30–35 screws per 4x8 sheet.
Paper / Fiberglass Joint Tape
Total Surface Area (with 10% waste)
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Guide
How to calculate drywall for a room
Drywall is sold in standard 4x8 ft (32 sq ft) or 4x12 ft (48 sq ft) sheets. Professional installers prefer 4x12 ft sheets because they eliminate 25% of taped butt joints on walls longer than 8 feet.
Measure Walls and Ceiling
Calculate gross wall square footage: 2 × (Length + Width) × Height. Add ceiling area (Length × Width).
Add 10% Waste
Drywall requires cuts around electrical boxes, corners, and door headers. Add 10% for cutting waste.
Divide by Sheet Area
Divide total square footage by 32 (for 4x8) or 48 (for 4x12) and round up.
Mathematics
Formulas used
Drywall Sheet Count
Ceil(((Wall Area + Ceiling Area) × 1.10) / Sheet Sq Ft)Total sheets required including cut waste.
Answers & FAQ
Frequently asked questions
Should I buy 4x8 or 4x12 drywall sheets?▼
4x8 sheets are lighter (~55 lbs) and easiest for 1 or 2 people to carry through stairwells. 4x12 sheets (~80 lbs) require two people but produce 25% fewer joints to tape.
How many screws do I need per sheet of drywall?▼
Plan for about 32 to 36 screws per 4x8 sheet (screws spaced every 12 inches on ceilings and 16 inches on walls).
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