Drywall Material Calculator
How to Use the Drywall Calculator
Planning a renovation requires precision to avoid overspending on materials or frequent trips to the hardware store. This drywall calculator helps you estimate the number of sheets, joint compound, and fasteners needed for any rectangular room. To get started, measure the length, width, and height of your room in feet.
The Math Behind the Calculation
To calculate the wall area, we use the formula: Area = 2 * (Length + Width) * Height. If you are including the ceiling, we add (Length * Width) to that total. We then subtract standard deductions for openings: approximately 21 sq ft per door and 12 sq ft per window. Finally, we apply a waste factor (typically 10%) to account for cuts and scraps.
Choosing the Right Sheet Size
- 4′ x 8′: The industry standard. Easy to transport and handle for DIY projects.
- 4′ x 10′: Excellent for rooms with 10-foot ceilings to eliminate horizontal seams.
- 4′ x 12′: Primarily used by professionals in large spaces to minimize the number of joints.
Realistic Estimation Example
Suppose you have a room that is 10ft long, 10ft wide, and 8ft high with one door and one window. You are using 4×8 sheets and want to include the ceiling.
- Wall Area: 2 * (10+10) * 8 = 320 sq ft
- Ceiling Area: 10 * 10 = 100 sq ft
- Total Gross: 420 sq ft
- Deductions: 21 (door) + 12 (window) = 33 sq ft
- Net Area: 387 sq ft + 10% waste ≈ 426 sq ft
- Sheets Required: 426 / 32 = 13.3 (Round up to 14 sheets)
Don't Forget the Finishings
Drywall isn't just about the boards. For every 1,000 square feet of drywall, you generally need about 9.4 gallons of joint compound, 370 feet of tape, and roughly 5 lbs of drywall screws. Our calculator provides these estimates based on your specific project size to ensure you have everything needed for a smooth finish.