Calculate your total wall area, subtract openings, add your ceiling if needed, then divide by the sheet size. Always add a waste factor — drywall cuts around outlets, windows, and corners generate significant scrap.
The Formula
Wall Area = 2 × (Length + Width) × Height. Subtract 21 sq ft per door and 15 sq ft per window. Add ceiling (L × W) if drywalling the ceiling. Divide by 32 (for 4×8 sheets) and round up.
Waste Factors by Room Type
Simple rectangular room — 10% waste is sufficient
Rooms with many windows/doors — 15% to account for extra cuts
Angled ceilings or complex shapes — 15–20% waste
What Else Do You Need?
Joint compound: 1 bucket (4.5 gal) covers approximately 200 sq ft per coat
Drywall screws: 1 lb box for every 200 sq ft (approx. 32 screws per sheet at 16" OC)
Joint tape: 1 roll (75 ft) for every 2–3 sheets
Corner bead: measure linear feet of all outside corners
Primer: always prime before painting new drywall
Drywall quantities locked in?
Build the full proposal in BuildQuotes or invoice the job directly.