How the estimate works
area = walls (2 × (L + W) × H) + ceiling (L × W) − openings × 20
sheets = ceil( area × 1.10 waste ÷ sheet sq ft )
screws = sheets × 32 mud = area × 0.053 lb
tape = area × 0.37 ft
The 10% waste factor covers offcuts around openings and bad breaks. Drywall is cheap —
running one sheet short on a Sunday afternoon isn't.
Finishing supplies per 1,000 sq ft of board
| Item | Amount |
|---|
| Joint compound (all-purpose) | ~53 lb (one 4.5 gal bucket) |
| Paper or mesh tape | ~370 ft (one 500 ft roll) |
| Screws 1¼″ coarse | ~1,000 (3–4 lb) |
| Corner bead | Per outside corner, 8 ft lengths |
Frequently asked questions
How many sheets of drywall do I need for a 12×12 room?
A 12×12 room with 8 ft ceilings has 384 sq ft of wall plus 144 sq ft of ceiling = 528 sq ft. With 10% waste that is about 19 sheets of 4×8 drywall (32 sq ft each).
Should I use 4×8 or 4×12 sheets?
4×12 sheets mean fewer joints to finish — the pros' choice for long walls and ceilings. 4×8 sheets are lighter (about 55 lb vs 82 lb for ½″) and fit through stairwells, which usually decides it for DIY work.
How many screws per sheet of drywall?
About 32 screws per 4×8 sheet on walls (16″ stud spacing, screws every 16″ in the field and 8″ on edges) and about 36 on ceilings where 12″ field spacing is standard. One pound of 1¼″ coarse screws is roughly 300 screws.
How much joint compound per square foot?
Plan on about 0.053 lb per sq ft of board for a standard 3-coat tape-and-finish — one 4.5-gallon bucket (about 61.5 lb) finishes roughly 1,000–1,200 sq ft.
What thickness of drywall should I use?
½″ is standard for walls and ceilings on 16″ framing. Use ⅝″ Type X where fire rating is required (garages, between units) and on ceilings with 24″ joist spacing to prevent sag. Moisture-resistant (green/purple) board goes in bathrooms outside wet areas.