Drywall Calculator
Enter your total wall (and optional ceiling) area to calculate how many standard drywall sheets you need, including a waste allowance for cuts.
Sheets needed
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Enter your area to calculate.
How the Drywall formula works
A coverage-based calculation using a standard sheet size:
Sheet area = Sheet width × Sheet length (commonly 4×8 ft = 32 ft²) Sheets needed = ceil( Total area × (1 + Waste%) / Sheet area )
Step-by-step calculation
- Add up total wall area (and ceiling area, if drywalling that too).
- Divide by a single sheet's area (commonly 32 ft² for a standard 4×8 sheet).
- Increase by your waste percentage and round up to a whole sheet.
Worked example
A room with 480 ft² of combined wall and ceiling area, using standard 4×8 (32 ft²) sheets, with 10% waste: Sheets = ceil(480 × 1.10 / 32) = ceil(16.5) = 17 sheets.
Frequently asked questions
What's a standard drywall sheet size?
4×8 feet (32 ft²) is the most common size for walls, though 4×12 sheets are also used to reduce seams on larger walls — check which size you're planning to use.
How much waste allowance is typical for drywall?
10% is a common general allowance, though rooms with many corners, windows, or odd angles may need more to account for extra cuts.