How we worked it out
Updated as you change the numbers.
- Wall area = 2 × (12 + 10) × 8 = 352 sq ft, less 36 sq ft of openings = 316 sq ft.
- Ceiling = 12 × 10 = 120 sq ft. Total 436 sq ft.
- With 10% extra: 436 × 1.1 = 479.6 sq ft.
- Sheets = 479.6 ÷ 32 sq ft per sheet = 14.99, rounded up to 15.
Method and assumptions
The calculator adds up the wall area (the room’s perimeter × the wall height) and the ceiling, subtracts 21 sq ft per door (3 × 7 ft) and 15 sq ft per window (3 × 5 ft), adds your waste allowance and divides by the area of one sheet.
This is an area estimate. A sheet-by-sheet layout of each wall can come out a sheet or two different, especially with tall walls or many openings.
Tips
- Ceilings are usually hung first, then the walls, with the top wall sheet pushed up to support the ceiling edge.
- Use moisture-resistant board in bathrooms and fire-rated (Type X) board where your building code calls for it, such as between a garage and the house.
- Hanging sheets horizontally on 8 ft walls usually means fewer, easier-to-finish seams.
Questions
How many sheets of drywall for a 12 × 12 room?
With 8 ft walls, the walls are 384 sq ft and the ceiling 144 sq ft. Less one door and one window (36 sq ft), that is 492 sq ft. With 10% extra, it takes 17 sheets of 4 × 8 ft.
Sources
Method and figures checked on . Every worked answer on this page is covered by an automated test. Found a mistake? Tell us.