Drywall calculator
Enter the room’s size, choose a sheet size, and decide whether the ceiling is included.
Drywall sheets
17 sheets
- Wall area
- 334 sq ft
- Total area
- 478 sq ft
How it works
The calculator adds up wall area (perimeter × height), subtracts about 20 square feet per door and 15 per window, and adds the ceiling if you include it. It then adds your cut allowance and divides by the area of one sheet: 32 square feet for 4×8, 40 for 4×10, 48 for 4×12.
Example
With room length 12 ft, room width 12 ft, wall height 8 ft, include the ceiling: yes, doors 1, windows 2, sheet size: 4 × 8 ft, extra for cuts 10%, the answer is 17 sheets.
Tips before you buy
- Longer sheets mean fewer seams to tape, but they’re heavy. A 4×12 sheet of 1/2 inch drywall weighs roughly 70–80 lb.
- Hang the ceiling first, then the walls, so the wall sheets help hold up the ceiling edges.
- Garages and some other areas require fire-rated drywall. Check local code before you buy.
- Use moisture-resistant board in bathrooms, and cement board behind tile in showers.
Common questions
How many sheets of drywall for a 12×12 room?
With 8-foot walls, one door and two windows, and the ceiling included: about 17 sheets of 4×8, with 10% extra for cuts.
How much extra drywall should I buy?
About 10% for a typical room. Rooms with lots of corners, openings or angled ceilings need more.
Should drywall be hung horizontally or vertically?
Horizontally is the common choice on walls up to 8–9 feet. It usually means fewer and easier seams.