How many sheets of drywall for 400 sq ft?
To board 400 sq ft you need about 14 sheets of 4 × 8 ft (32 sq ft) drywall, including a 10% cutting allowance — that buys 448 sq ft, leaving roughly 48 sq ft for offcuts.
- Area
- 400 sq ft
- Net area
- 400 sq ft
- With allowance
- 440 sq ft
- Purchased
- 448 sq ft
- Leftover (est.)
- 48 sq ft
Based on 4 × 8 ft sheets (32 sq ft each) and a 10% cutting allowance. Enter your own area and sheet size in the calculator.
Change the numbers in the drywall calculator →How this is worked out
Drywall calculator uses the same method as every tool here: measure the area, add a visible allowance, divide by what one sheet covers, and round up. The number above is the honest planning quantity — not an exact sheet layout. Confirm coverage on your product before buying.
buy = net area × (1 + allowance) ÷ per-sheet coverage → round up
Other sizes
Related
- Drywall calculator — change any number for your job
- Room material planner — every material on one shopping list
- Drywall sizes and thickness
- Why you buy more than you use
Frequently asked questions
How many 4 × 8 sheets of drywall is 400 sq ft?
About 14 sheets once a 10% cutting allowance is added (440 sq ft to buy ÷ 32 sq ft per sheet, rounded up).
How many 4 × 12 sheets instead?
Switch sheet size in the drywall calculator — 4 × 12 ft sheets cover 48 sq ft each, so you need fewer of them for the same 400 sq ft.