How Many Sheets of Drywall Do I Need?
Enter your room dimensions to calculate drywall sheets for walls and ceiling. Doors and windows are automatically subtracted.
How to Calculate Drywall Sheets
Calculate total wall area by multiplying perimeter by ceiling height. Subtract 21 sq ft per door and 15 sq ft per window. Divide by the sheet area (32 sq ft for 4×8 sheets) and add 10% for waste.
Standard drywall sheets are 4×8 ft (32 sq ft). For rooms with 9-ft ceilings, 4×12 sheets reduce seams and save time on finishing.
Drywall Types and When to Use Each
| Type | Thickness | Best For |
|---|---|---|
| Standard (white board) | ½" | Most walls and ceilings |
| Lightweight | ½" | Same applications, easier to handle |
| Moisture-resistant (green/purple) | ½" | Bathrooms, kitchens, laundry rooms |
| Fire-resistant (Type X) | ⅝" | Garages, around fireplaces, code-required areas |
| Soundproof | ½"–⅝" | Home theaters, bedrooms |
Standard ½" drywall is the right choice for most wall and ceiling applications. Use moisture-resistant board (green or purple board) in bathrooms and near any water source — standard drywall behind tile will absorb moisture and eventually fail. Garages attached to living spaces typically require ⅝" Type X fire-resistant board by code.
Drywall Finishing Costs
Material cost is only part of drywall work. Finishing (taping, mudding, and sanding) can be as time-consuming as hanging. Professional drywall finishing runs $1.50–$3.00 per square foot of finished surface. A typical 12×12 room with 8-ft ceilings has about 550 sq ft of wall and ceiling area — finishing costs $825–$1,650 in labor.
DIY drywall finishing is achievable but requires practice. The three-coat process (tape coat, fill coat, finish coat) takes 3–5 days for a standard room due to drying time between coats. Feathering the edges smoothly for an invisible seam is the hardest skill — budget for practice on a small area first.