Drywall Calculator
Buy Drywall at Home Depot →How this calculator works
Drywall sheets come in a standard 4 ft × 8 ft size, covering 32 square feet each. This calculator divides your total wall (and ceiling, if included) area by 32 to get the sheet count, rounding up since drywall is sold as whole sheets.
Formula: Sheets = Wall/ceiling area (sq ft) ÷ 32 sq ft per sheet.
Worked example
A room with 16 ft × 8 ft of combined drywall surface (128 sq ft):
- Sheets: 128 ÷ 32 = 4.0 sheets
- At $13/sheet, that’s $52.00 before waste.
- With 10% waste added: 4.4 → rounds up to 5 sheets, or $65.00.
Coverage reference
| Wall/ceiling area | Sheets needed |
|---|---|
| 128 sq ft | 4 sheets |
| 320 sq ft | 10 sheets |
| 640 sq ft | 20 sheets |
How to measure your area
Measure the height and width of each wall section and multiply, then add all sections (and the ceiling, if applicable) together. Standard 8 ft ceilings mean most residential walls are measured in multiples of the 8 ft sheet height, which minimizes waste.
Frequently asked questions
How many sheets of drywall do I need?
A standard drywall sheet is 4 ft x 8 ft, covering 32 square feet. Enter your combined wall and ceiling area and this calculator converts it directly into sheet count.
Do I need to include the ceiling in my area?
Yes, if you're drywalling the ceiling too — add ceiling square footage to your wall square footage before entering it, or run the calculator twice (once for walls, once for the ceiling) if you want the totals separately.
How much waste should I add for drywall?
10% is standard for a room with a normal number of doors and windows. Rooms with unusual angles, lots of openings, or unusual layouts may need 15%.
Should I subtract door and window openings from my area?
Small openings usually aren't worth subtracting since cut-off pieces are rarely large enough to reuse elsewhere — the standard waste percentage already accounts for this. For large openings (e.g. sliding doors), you can subtract the exact square footage.
Estimates only. Verify quantities with your supplier before purchasing.