Drywall Calculator (Sheets, Screws, Mud and Tape)

Enter the room, choose the sheet size and this drywall calculator counts sheets for the walls and ceiling with a waste allowance, then estimates the screws from USG’s spacing (16 in on walls, 12 in on ceilings), the ready-mixed joint compound and the paper tape. Subtract only large openings; small ones come out of the waste. For mud and tape alone, the joint compound calculator gives more detail.

Drywall sheets calculator

How it works

Wall area = 2 × (length + width) × height − openings; ceiling = length × width
Sheets = area × (1 + waste) ÷ sheet area, rounded up separately for walls and ceiling
Screws = sheets × framing members crossed × screws per member: at 16 in framing a 4 × 8 sheet crosses 7 members, with 4 screws each on walls (16 in spacing) and 5 on ceilings (12 in spacing), per USG
Compound = 10 gal per 1,000 sq ft; tape = 370 ft per 1,000 sq ft (USG product data)

Worked example

A 14 × 12 ft room with 8 ft walls and the ceiling, 40 sq ft of door and window openings, 4 × 8 sheets, 16 in framing, 10% waste:

Room length: 14 ft
Room width: 12 ft
Wall height: 8 ft
Include the ceiling: Yes
Openings to subtract: 40 sq ft
Sheet size: 4 × 8 ft (32 sq ft)
Waste: 10%
Framing spacing: 16 in on centre

The calculator gives:

Sheets: 19 × 4 × 8 ft (13 walls + 6 ceiling, 10% waste)
Screws: about 574 (1 lb of 1-1/4 in screws at roughly 1,000 per lb) at 16 in on walls, 12 in on ceilings
Joint compound: 5.4 gal (2 × 4.5 gal pails) at 10 gal per 1,000 sq ft
Joint tape: 201 ft (1 × 250 ft rolls)
Drywall area: 544 sq ft (walls 376, ceiling 168)

The walls are 376 sq ft net and the ceiling 168 sq ft: 13 sheets for the walls and 6 for the ceiling, 19 in all. About 574 screws, 5.4 gallons of compound (two 4.5 gal pails) and 200 ft of tape. With 4 × 12 sheets the count drops to 13 and only the two 14 ft walls need a butt joint, which saves more finishing time than the sheets cost.

Material and waste notes

Which sheet size and thickness: see the drywall sizes and thickness guide for walls, ceilings, garages and bathrooms.
Hang ceilings first, then walls, with sheets running perpendicular to the framing. 12 ft sheets across an 8 ft wall leave only one horizontal seam.
Screws are counted per sheet at the framing you enter; the field and edge spacing follow USG’s non-fire-rated guidance. Fire-rated assemblies have their own schedules.
Corner bead, adhesive, ceiling boxes and moisture-resistant board for bathrooms are extra.
Use 1-1/4 in screws for 1/2 in board on wood; 5/8 in board needs 1-5/8 in.
A 4 × 8 sheet of 1/2 in drywall weighs about 50 lb; ceilings are a two-person or lift job.

Frequently asked questions

How many sheets of drywall for a 12×12 room?

About 17 sheets of 4 × 8 with a door and a window subtracted, including the ceiling and 10% waste (12 for the walls, 5 for the ceiling).

How many screws per sheet of drywall?

About 28 on a wall and 35 on a ceiling for a 4 × 8 sheet over 16 in framing, at USG’s 16 in and 12 in spacing. A pound of 1-1/4 in screws is roughly 1,000.

How much drywall mud per sheet?

About 0.32 gal per 4 × 8 sheet at USG’s 10 gal per 1,000 sq ft, plus about 12 ft of tape.

Should I use 4×8 or 4×12 drywall?

4 × 12 sheets on 8 ft walls run wall to wall in most rooms and eliminate butt joints, the hardest joints to finish. They are heavy and need a wide path into the room.

Do I subtract doors and windows from drywall?

Subtract large openings like doors and big windows; the pieces cut from small openings are rarely reusable, so leave those in.

Sources

Last reviewed: 26 September 2026. The calculation is covered by automated tests with known answers taken from the sources above. Found an error? Please let us know.