How this drywall calculator works
Drywall is an area takeoff: wall perimeter times height, plus the ceiling if you're doing it, minus openings — then whole sheets with waste, and the finishing materials keyed to the same area:
sheets = area × (1 + waste%) ÷ 32 · 4×8 sheet; 48 for 4×12
Worked example: drywall for a 12 × 12 room
Walls: 2 × (12 + 12) × 8 = 384 ft²; ceiling adds 144 for 528 ft². With 10% waste that's 580.8 ft² — 19 sheets of 4×8 (about $285), hung with roughly 608 screws, finished with 6 gallons of compound and one roll of tape.
How much mud, tape and screws per sheet?
| Material | Per 100 ft² |
|---|---|
| Screws (16″ o.c. framing) | ≈ 100 |
| Joint compound, ready-mix | ≈ 1 gal |
| Paper tape | ≈ 37 lf |
Hanging drywall in the right order
- Ceilings first, so the wall sheets support the ceiling edges.
- Perpendicular to framing and stagger end joints — butt joints in a straight line telegraph through paint.
- Cut openings after hanging where you can: hang over doors and windows, then rout them out — fewer measured cuts, tighter fits.
- ½ in board is standard for walls, ⅝ in for ceilings under trusses 24″ o.c. and anywhere fire code says so.
Drywall FAQ
How many sheets of drywall do I need for a 12 × 12 room?
19 sheets of 4×8, walls and ceiling, with 10% waste — 384 ft² of wall plus a 144 ft² ceiling. In 4×12 sheets it drops to 13. Subtract door and window area in the openings field before trusting either number.
How many screws per sheet of drywall?
About 32 per 4×8 sheet on 16 in framing — screws every 12 in in the field and 8 in on edges. That is one screw per square foot, so the default room runs about 610. Buy the 1¼ in coarse-thread box for ½ in board on wood studs.
How much joint compound per sheet of drywall?
Plan on about 1 gallon of ready-mixed compound per 100 ft² of board for a taped three-coat finish — roughly 6 gallons (a 5-gal bucket plus a pail) for the default room. Texture and skim coats add more.
Should I use 4×8 or 4×12 drywall sheets?
4×12 means fewer joints to tape — the default room drops from 19 sheets to 13 and loses several butt joints — but the sheets weigh ~50% more and need two sets of hands and a clear path in. Solo DIY rooms usually run 4×8; crews run 12s.
How much does it cost to drywall a room?
The default room is about $285 in board at $15 a sheet, plus roughly $40–60 of screws, tape and compound. Hung and finished by a contractor, drywall typically runs $2–3.50 per square foot in 2026 — finishing labor is most of it.
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