The Drywall Calculator tells you how many sheets of drywall you need for a room, based on wall dimensions and sheet size. Simply fill in the fields above and click Calculate to get an instant result.
This calculator is part of Calculate Wiki’s Construction Calculators collection.
What You’ll Need
- Total Wall Length (combined)
- Wall Height
- Sheet Width and Sheet Length
- Waste Allowance
Formula Used
Wall area = Combined length × Height
Sheets needed = (Wall area × (1 + Waste%)) ÷ Sheet area
Example Calculation
Using example inputs — Combined Length = 40 ft; Height = 8 ft; Sheet = 4 ft × 8 ft; Waste = 10% — the Drywall Calculator returns:
| Value | Result |
|---|---|
| Wall area | 320 sq ft |
| Total area (with waste) | 352 sq ft |
| Sheets needed | 11 |
11 drywall sheets needed.
Helpful Information
Results from the Drywall Calculator are estimates based on standard formulas used in the construction calculators field. Doesn’t account for door/window cutouts, which can reduce the sheet count slightly.
Frequently Asked Questions
Is the Drywall Calculator free to use?
Yes — the Drywall Calculator on Calculate Wiki is completely free, with no sign-up required.
How accurate is the Drywall Calculator?
The Drywall Calculator uses a standard, well-documented formula from the construction calculators field. Results are for informational and planning purposes.
Can I use this on my phone?
Yes, this calculator is fully mobile-friendly and works on any modern browser.
What does the result mean?
For the example values shown above (40 ft combined wall length, 8 ft height), you’d need 11 sheets of 4×8 ft drywall.