How to Calculate Drywall
Formula: Wall area = 2×(L+W)×H. Ceiling = L×W. Subtract openings. Sheets = ceil(area ÷ sheet area × 1.1).
Drywall Thickness Guide
| Thickness | Common Use |
|---|
| 1/4 inch | Curved walls, resurfacing |
| 3/8 inch | Repairs, lightweight partitions |
| 1/2 inch | Standard walls & ceilings |
| 5/8 inch | Garages, fire-rated, sound control |
Material Estimates per Sheet (4×8)
- Screws: ~32 pieces (1 lb ≈ 170 screws)
- Joint compound: ~0.5 gal (3 coats)
- Tape: ~12 ft (seams only)
FAQ
How many sheets for 12×12 room?
Walls 384 + ceiling 144 − 35 openings = 493 sq ft. ÷ 32 × 1.1 = 17 sheets of 4×8.
4×8 or 4×12?
4×12 has 33% fewer seams but is heavier. 4×8 is standard for DIY. Use 4×12 for ceilings if possible.
How much joint compound?
~0.5 gal per 4×8 sheet for 3 coats. 5-gal bucket covers ~10 sheets.
How many screws per sheet?
~32 screws per 4×8 sheet. 12" on edges, 16" in field. 1 lb = ~170 screws.