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Drywall Calculator
Drywall is a system, not just sheets: compound, tape and screws scale with the board area. Enter the room and get the full takeoff — sheets in your choice of 4x8, 4x10 or 4x12, plus joint compound, paper tape and screws figured at USG's published estimating rates.
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Compound, tape and screw rates are USG's published estimating figures (about 9 gal of compound, 370 ft of tape and 1,000 screws per 1,000 sq ft of board). Heavy texture, high finish levels and ceilings use more compound — when in doubt, the extra pail is cheap insurance.
How it works
Sheets = board area × (1 + waste %) ÷ sheet area, rounded up
The finishing supplies follow USG's estimating rates, the same ones pro estimators use:
| Supply | Rate per 1,000 sq ft of board | Sold as |
|---|---|---|
| Ready-mix joint compound | ~9 gallons | 4.5 gal pails |
| Paper joint tape | ~370 ft | 250 ft rolls |
| Screws, 16 in framing | ~1,000 | 5 lb boxes (~1,190 screws) |
| Screws, 24 in framing | ~850 | 5 lb boxes |
Sheet size is a logistics choice, not a math one: 4x12 sheets mean fewer joints to finish but need two people and a stairwell they can actually turn in; 4x8s are the one-person, fits-in-the-truck default. Whatever the size, hang ceilings first and walls from the top down, and stagger butt joints so four corners never meet at one point.
Worked example
A 12×12 ft room with 8 ft ceilings, 1 door and 2 windows, ceiling included: walls are 384 − 21 − 30 = 333 sq ft, plus 144 sq ft of ceiling = 477 sq ft of board. In 4x8 sheets at 10% waste: 477 × 1.1 ÷ 32 = 16.4, so 17 sheets. Finishing at USG rates: 4.3 gal of compound (1 pail), 176 ft of tape (1 roll), and about 477 screws — well inside one 5 lb box.
Frequently asked questions
How many sheets of drywall do I need for a 12x12 room?
17 sheets of 4x8 for walls and ceiling in a 12x12 room with 8 ft ceilings, standard door and window deductions, and a 10% waste allowance (477 sq ft of board). Walls only, it's 12 sheets. Bigger 4x12 sheets cut the count to 11 for the whole room.
How much joint compound per sheet of drywall?
About 0.3 gallons per 4x8 sheet — USG's estimating rate is roughly 9 gallons of ready-mix per 1,000 sq ft of board for taping and finishing coats. Texture and Level 5 finishes use more; a simple tape-and-two-coats job in a small room can use a bit less.
How many screws are in a sheet of drywall?
Around 28–32 for a 4x8 sheet on walls framed 16 in on center — roughly 1,000 screws per 1,000 sq ft of board. Ceilings get closer spacing and run higher. A 5 lb box of 1-1/4 in coarse-thread screws holds about 1,190 screws and covers roughly 35–40 sheets.
Should I use 4x8 or 4x12 drywall sheets?
4x12 sheets have fewer butt joints, so they finish faster and flatter — if you have a helper and the sheets can physically reach the room. 4x8s win for solo work, tight stairs and small rooms where a 12 ft sheet can't turn. The board area is identical either way; only the sheet count changes.
Do I drywall the ceiling or walls first?
Ceiling first, then walls starting at the top so the wall sheets help support the ceiling edges. And yes, include the ceiling in your sheet count from the start — it's the surface most often forgotten in a first estimate.
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About the author
Harrison Alley is a web publisher and data enthusiast based in Dallas, Texas. He built Urbarama’s remodeling calculators and maintains them.
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