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How Much Drywall Do I Need?

The number of drywall sheets depends on your total wall (and ceiling) area and the sheet size. A standard 4×8 sheet covers 32 sq ft — add 12% waste for cuts and edges.

Tom Harrington · Licensed General Contractor

18 years · Licensed GC · OSHA 30

Tom has built and renovated over 400 residential projects across the Mid-Atlantic. He specializes in concrete, framing, and exterior hardscape.

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Drywall Calculator — sheets, joint compound, and tape

Enter your exact dimensions for a personalized estimate →

The quick formula

Sheets = ceil(Net wall area × 1.12 ÷ sheet sq ft)

Sheet size reference

Sheet sizeSq ftSheets per 100 sq ft (12% waste)
4 × 8 ft32 sq ft4 sheets
4 × 12 ft48 sq ft3 sheets
4 × 16 ft64 sq ft2 sheets

Sheets needed by room (4×8 sheets, 8 ft ceiling, 12% waste)

RoomWall areaSheets (walls only)Add for ceiling
8 × 10 ft288 sq ft10 sheets+3 sheets
10 × 12 ft352 sq ft13 sheets+4 sheets
12 × 12 ft384 sq ft14 sheets+5 sheets
12 × 16 ft448 sq ft16 sheets+7 sheets

Supplies per 100 sq ft of drywall

SupplyEstimate
Joint compound1 gallon (3 coats)
Drywall tape1 roll (75 ft) per 3 sheets
Drywall screws (1 lb)~35 per 4×8 sheet

How to measure

  1. Each wall: length × ceiling height in feet
  2. Add all walls: total wall area
  3. Add ceiling if needed: room length × width
  4. Subtract openings (optional): 21 sq ft per door, 15 sq ft per window
  5. Apply 12% waste

Use the Drywall Calculator for your exact room dimensions with automatic door/window deduction.

Frequently Asked Questions

How many sheets of drywall do I need for a 12×12 room?

A 12×12 room with 8-foot ceilings has about 384 sq ft of wall area. After subtracting 1 door and 2 windows (57 sq ft), net area is 327 sq ft. With 12% waste and 4×8 sheets (32 sq ft each), you need 12 sheets. Add 3 more for the ceiling (144 sq ft ÷ 32 = 5 sheets).

How many sheets of drywall come in a bundle?

Drywall is typically sold by the sheet individually at home improvement stores. Delivered orders may come in bundles of 2 sheets (face-to-face). You can usually order any quantity.

Should I use 4×8 or 4×12 drywall sheets?

4×8 sheets are standard and easiest to handle. 4×12 sheets create fewer seams (which means less taping and finishing work) but are heavier and harder to lift alone — especially for ceilings. Most DIYers use 4×8.

How much joint compound do I need for drywall?

As a rough estimate, plan on about 1 gallon of joint compound per 100 sq ft of drywall for 3 coats (tape coat, filler coat, finish coat). A 5-gallon bucket covers about 500 sq ft of drywall.

Do I subtract doors and windows from my drywall calculation?

You can, but most contractors do not make large deductions — the cutouts become usable pieces for corners and other areas. The calculator makes the deduction as an option, but add some back in for partial sheets used elsewhere.

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