Drywall calculator: how many sheets of drywall do I need?
10 sheets
320 square feet of wall takes 10 sheets of 4 by 8 ft drywall, because one 4 by 8 sheet covers 32 square feet. Add your own waste allowance for cuts around openings.
320 square feet of surface · for 40 × 8 ft
Run your own numbers
Enter it the way you measured it: 4.5, 4 1/2,
3/8 or 10' 6".
10 sheets
320 square feet of surface
A worked example
A 27 by 9 ft wall with a 10 % waste allowance, in 4 × 12 ft panels needs 6 panels. 243 square feet at 48 square feet per panel is 5.06, and the allowance takes it to 6.
What else it is called
Drywall is also sold as Sheetrock, which is a USG brand name used generically the way people say Kleenex, and as gypsum board or wallboard. Same panel, same coverage, so the count on this page does not change with the name on the label.
Common sizes
| Area | 4 × 8 ft | 4 × 9 ft | 4 × 10 ft | 4 × 12 ft |
|---|---|---|---|---|
| 8 × 8 ft — 64 sq ft | 2 | 2 | 2 | 2 |
| 10 × 10 ft — 100 sq ft | 4 | 3 | 3 | 3 |
| 10 × 12 ft — 120 sq ft | 4 | 4 | 3 | 3 |
| 12 × 12 ft — 144 sq ft | 5 | 4 | 4 | 3 |
| 12 × 16 ft — 192 sq ft | 6 | 6 | 5 | 4 |
| 16 × 20 ft — 320 sq ft | 10 | 9 | 8 | 7 |
| 20 × 20 ft — 400 sq ft | 13 | 12 | 10 | 9 |
Pieces, rounded up, with no waste allowance added.
Where the numbers come from
- Panel coverage is the nominal size you select, multiplied out: a 4 by 8 ft sheet is 32 square feet. No claim of ours is involved — you tell the page which panel you are buying.
This counts panels for a flat wall. It does not subtract doors and windows: leaving them in is what most people want, because the offcuts rarely reach the next wall.
Last checked September 26, 2026. How this site is made.