How many sheets of drywall do I need? Sheets, tape, mud and screws
Add up the wall area (the room’s perimeter times its height) and the ceiling if you are covering it, add about 10% for cuts and divide by the sheet size: 32 sq ft for a 4 × 8 ft sheet, 48 for a 4 × 12.
A 12 × 10 ft room with 8 ft walls has 352 sq ft of wall: 11 sheets of 4 × 8 before extra, 13 with 10% extra.
Worked example
Example: a 12 × 10 ft room with 8 ft walls and no openings, walls only, one layer and 10% extra.
This example gives 13 drywall sheets by area.
- Surface area: 352 sq ft
- ceil(352 × (1 + 10/100) ÷ 32) = 13
Other calculators for this job
Every step of a paint and drywall project: measure, the list, what it costs and the quotes.
Which drywall to buy: thickness and sheet size
From USG’s installation guide and panel data sheets. Sheets are 4 ft wide and 8 to 16 ft long; UltraLight also comes 54 in wide, which covers a 9 ft wall in two rows. USG calls 12 ft sheets hung across the studs ideal for walls, because they leave the fewest joints. At USG’s 1.25 lb a square foot, a 4 × 8 ft sheet of 1/2 in UltraLight weighs about 40 lb and a 4 × 12 ft sheet about 60; a 4 × 8 ft sheet of 5/8 in UltraLight Firecode X weighs about 61 lb.
| Sheet | Walls: studs up to | Ceilings: joists up to | Use it for |
|---|---|---|---|
| 1/2 in UltraLight | 24 in apart | 24 in apart, whichever way the sheets run, also under a water-based texture | Walls and ceilings that need no fire rating: USG’s lightweight, sag-resistant sheet |
| 1/2 in regular | 24 in apart | 24 in with the sheets across the joists (16 in under a water-based texture); 16 in with them along the joists, and not under a water-based texture | Walls and ceilings |
| 5/8 in Firecode X | 24 in apart | 24 in with the sheets across the joists; 16 in along them, and not under a water-based texture | Walls and ceilings where the building code asks for fire resistance |
| 3/8 in | 16 in apart | 16 in, sheets across the joists only; not below an unheated space or under a water-based texture | A thinner sheet on framing 16 in apart |
| 1/4 in | Never on its own | Never on its own | Covering an existing wall or ceiling |
What changes the order?
Adding the ceiling adds its length times its width to the wall area.
| Calculator input | Result from those inputs |
|---|---|
| Surfaces: walls | 13 drywall sheets by area |
| Surfaces: walls and ceiling | 17 drywall sheets by area |
Try your own measurements in the drywall area calculator.
Measure walls and ceilings separately
Wall area is the room’s perimeter times its height; the ceiling is its length times its width. Floor area is not wall area. Take out only big openings: the piece cut from a small window is usually waste anyway.
Pick the sheet size
4 × 8 ft sheets are the easiest to carry; 4 × 12 ft sheets leave fewer joints to tape on long walls. Hanging sheets across the studs usually means fewer joints; the installer decides the layout.
Tape, mud and screws
Tape runs along every joint and inside corner. The calculator counts tape rolls and compound from USG’s coverage figures, and screws from USG’s spacing: 28 for a 4 × 8 sheet on a wall. Corner bead is counted from the length of outside corners you enter.
What the quote should say
Agree on the finish you expect, smooth and ready for paint or textured, and who primes it. Framing repairs, hidden damage and matching an old texture are separate lines.