Drywall Calculator
Calculate how many drywall sheets you need for a room. Enter room dimensions, ceiling height, number of doors and windows, and get the total sheet count for 4×8 and 4×12 panels.
Formulas, assumptions, and rounding are documented in our calculator methodology.
Waste Factor
4×8 Sheets Needed
12
sheets (incl. 10% waste)
Drywall Summary
- Wall Area
- 396.0 sq ft
- Door Deductions
- −20 sq ft
- Window Deductions
- −30 sq ft
- Net Area
- 346.0 sq ft
- Total with Waste
- 380.6 sq ft
- 4×8 Sheets (32 sq ft)
- 12 sheets
- 4×12 Sheets (48 sq ft)
- 8 sheets
Drywall Types and Thicknesses
½-inch drywall is standard for walls in most residential construction. ⅝-inch Type X is fire-rated and required by code in garages and attached structures. ⅜-inch is used for curved walls and repairs. Moisture-resistant (MR) drywall is used in bathrooms and kitchens — though cement board is preferred directly behind tile. Specialty soundboard products reduce sound transmission. Check local building codes for required types.
Finishing Levels Explained
Drywall finishing is graded in levels 0–5. Level 0: unfinished. Level 1: tape set (concealed areas). Level 2: one coat (substrate for tile). Level 3: two coats (heavy texture). Level 4: three coats sanded (flat paint, standard living areas). Level 5: skim coat over full surface (gloss paint, critical lighting). Most living areas require Level 4; Level 5 prevents 'picture-framing' under critical lighting.
Planning Your Drywall Project
Order 10–15% extra for cuts, waste, and future repairs. Store sheets flat or standing vertically — never lean at a steep angle. Use ring-shank drywall screws every 12 inches on studs for walls, every 12 inches on ceiling joists. A 4×8 sheet of ½-inch drywall weighs about 57 lbs — use a drywall lift or get a helper for ceiling installation.
Frequently Asked Questions
- Calculate total wall area: perimeter × ceiling height. Subtract ~20 sq ft per door and ~15 sq ft per window. Add ceiling area if applicable. Add 10% waste. Divide by 32 sq ft (4×8 sheet) to get number of sheets.
- A standard 4×8 drywall sheet covers 32 square feet. A 4×12 sheet covers 48 square feet. 4×12 sheets reduce the number of butt joints on tall walls but are heavier to handle.
- For 8 ft ceilings, 4×8 sheets hung horizontally minimize butt joints. For 9–10 ft ceilings, 4×12 sheets reduce joints further. For ceilings, 4×8 sheets hung perpendicular to joists are standard. Check sheet length against your stud/joist spacing.
- DIY material costs roughly $0.40–$0.65 per sq ft for standard ½-inch drywall. Professional installation (hang, tape, mud, sand) runs $1.50–$3.50 per sq ft depending on region and finish level. Moisture-resistant and fire-rated drywall cost more.