Drywall Calculator
✓ Your estimate
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Net Sq Ft
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Sheets
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Est. Screws
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Tape (lin ft)
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Compound (gal)
⚠ Screw, tape, and compound estimates are rough planning figures. Actual needs depend on stud spacing, finish level, and installer method. Confirm with your drywall supplier.
What the Result Means
Sheet count is your primary material estimate. Screws, tape, and compound are rough planning figures to help you budget and prepare -- actual quantities depend on stud spacing, finish level, and installer preference.
Once drywall is hung, primed, and painted, the paint calculator handles the paint estimate. For tile work in bathrooms, see the tile calculator. All interior tools are at the interior calculators page.
How the Calculation Works
Wall Area = 2 x (Length + Width) x Wall Height
Ceiling Area = Length x Width (if selected)
Deductions = (Doors x 21) + (Windows x 15) sq ft
Net Area = Wall Area + Ceiling Area - Deductions
Adjusted Area = Net Area x (1 + Waste %)
Sheets = Adjusted Area / Sheet Area
Screws ~32 per 4x8 sheet | Tape ~1.1 linear ft per sq ft | Compound ~1 gal per 100 sq ft
Worked Example
Example: 12 ft x 10 ft room, 8 ft walls, ceiling included, 4x8 sheets, 10% waste
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Wall area: 2 x (12 + 10) x 8 = 352 sq ft
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Ceiling: 12 x 10 = 120 sq ft
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Net area: 352 + 120 = 472 sq ft (no doors/windows in example)
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With 10% waste: 472 x 1.10 = 519 sq ft adjusted
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Sheets: 519 / 32 = 17 sheets (round up)
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Screws: 17 x 32 = ~544 screws | Compound: 472 / 100 = ~5 gallons
Ordering Notes
Assumptions Used by This Calculator
- Door deduction is 21 sq ft per door; window deduction is 15 sq ft per window.
- Sheet count is calculated from adjusted area divided by sheet size.
- Screws estimated at 32 per 4x8 sheet, scaled proportionally for larger sheets.
- Joint tape estimated at 1.1 linear feet per square foot of drywall (rough planning figure).
- Joint compound estimated at 1 gallon per 100 sq ft -- actual use varies by finish level (Level 1 through Level 5).
- Waste accounts for cuts around openings, breakage, and layout inefficiencies.
- This calculator does not account for framing, backer board, or fire-rated assemblies.
Frequently Asked Questions
How many drywall sheets do I need for a 12x12 room?
A 12x12 room with 8 ft ceilings has about 384 sq ft of wall area. With ceiling included, add 144 sq ft = 528 sq ft total. Using 4x8 sheets (32 sq ft each) with 10% waste, you need about 19 sheets.
Should I include the ceiling?
Yes, if you are drywalling the ceiling. Ceiling drywall is the same material but heavier to hang. Include ceiling square footage and plan for extra help or scaffolding during installation.
What size drywall sheet should I use?
4x8 ft sheets are standard and most widely available. 4x10 and 4x12 sheets create fewer seams, which reduces finishing labor. Larger sheets are harder to handle and may not fit in standard vehicles -- confirm delivery is available.
How much waste should I add for drywall?
10% is standard for simple rectangular rooms. For rooms with many angles, arches, or complex layouts, add 15-20%. Cutting around windows, doors, and outlets wastes material that cannot be reused.
How many screws per sheet of drywall?
A rough planning estimate is 32 screws per 4x8 sheet. Actual count depends on stud spacing (16 in or 24 in on center) and local code requirements.
How much joint compound do I need?
A rough estimate is 1 gallon per 100 sq ft of drywall. A 5-gallon bucket covers about 500-700 sq ft. You will typically apply 3 coats: tape coat, fill coat, and finish coat.
Should I hang drywall vertically or horizontally?
Horizontal hanging (perpendicular to studs) is standard for walls -- it creates fewer vertical seams and is stronger. For ceilings, drywall is always hung perpendicular to joists.
Disclaimer: This calculator provides estimates only. Screws, tape, and compound quantities are rough planning figures. Verify all quantities with your drywall supplier and consult local building code for your project. See all interior renovation calculators.