Drywall Calculator

Calculate the drywall sheets, screws, joint compound and tape to hang and finish a room.

Feet + inches
Sourced data
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Calculator

Room length

Room width

Wall height

Doors

Windows

Include the ceiling

Sheet size

Extra for waste

Price per sheet (optional)

Drywall sheets

493 sq ft to cover, plus 10% waste

Drywall screws: ~544
Joint compound (all-purpose): 5.4 gal
Paper joint tape: 202 ft

Compound pails

2 × 4.5 gal

Premixed all-purpose

Tape rolls

1 × 250 ft

or 500 ft rolls

How it works Formula, reference tables and pro tips

How the drywall estimate works

Wall area = 2 × (length + width) × height, minus about 20 sq ft per door and 15 per window.
Add the ceiling (length × width) if you're covering it.
Add 10% for waste and divide by the sheet size, rounding up.
Screws, compound and tape are scaled from the total board area.

Materials per 1,000 sq ft of drywall

Material	Amount
All-purpose joint compound (ready-mixed)	~10 gal
Lightweight joint compound	~9.4 gal
Paper joint tape	~370 ft
Screws (1 per sq ft)	~1,000

Which drywall to use

Type	Where
1/2" regular	Most interior walls
1/2" sag-resistant or 5/8"	Ceilings
5/8" Type X (fire-rated)	Garage walls and ceilings shared with the house, where code requires
Moisture/mold-resistant	Bathrooms, laundry rooms, basements
Cement board	Behind tile in showers and tub surrounds

Quick answers

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

With 8 ft walls, one door and one window, the walls are 349 sq ft and the ceiling 144 sq ft. With 10% waste that is 17 sheets of 4 × 8, or 12 sheets of 4 × 12.

How much joint compound do I need?

USG estimates about 10 gallons of all-purpose ready-mixed compound per 1,000 sq ft of drywall (around 9.4 gallons for lightweight compound). That is roughly two 4.5-gallon pails per 1,000 sq ft.

How many drywall screws per sheet?

About 32 screws for a 4 × 8 sheet and 48 for a 4 × 12, roughly one per square foot. Typical spacing is 12 inches on ceilings and 16 inches on walls.

How much drywall tape do I need?

Plan on about 370 ft of paper tape per 1,000 sq ft of drywall. Tape comes in 250 and 500 ft rolls.

Should I use 4×8 or 4×12 sheets?

4 × 12 sheets mean fewer seams to tape and finish, so they save time on long walls, but they are heavy and awkward for one person. 4 × 8 sheets are easier to carry and fit in most vehicles.

Sources

Last reviewed November 2, 2026.

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These calculators give estimates for planning and shopping. Product yields, densities and coverage vary by brand and site conditions, so check the label and your supplier. For structural work, follow your local building code and permit requirements.