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

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.