Drywall Calculator
Calculate the number of drywall sheets (sheetrock) needed for walls and ceilings with precise area calculations
Calculate Drywall Materials
Room Dimensions
Gross Area: 0.0 sq ft (0.0 m²)
Wall Area: 0.0 sq ft | Ceiling Area: 0.0 sq ft
Sloped Walls (Optional)
Check this if your room has triangular areas under sloped walls
Doors
Total door area: 21.0 sq ft
Windows
Total window area: 24.0 sq ft
Drywall Panel Specifications
Recommended: 10% for waste and cuts
Typical range: $6-$15
Drywall Calculation Results
Calculation: -45.0 sq ft ÷ 32 sq ft/panel × 1.10 (waste factor)
Area breakdown: Gross: 0.0 sq ft - Doors: 21.0 sq ft - Windows: 24.0 sq ft + Sloped: 0.0 sq ft
Panel size: 4' × 8' = 32 sq ft
Panels without waste: -1 panels
Room Analysis
Example Calculation
Standard Bedroom Example
Room: 12 ft × 10 ft × 8 ft (with ceiling)
Doors: 1 door (3 ft × 7 ft = 21 sq ft)
Windows: 2 windows (3 ft × 4 ft = 24 sq ft total)
Panel size: 4' × 8' = 32 sq ft per panel
Calculation Steps
1. Wall area: 2(12×8) + 2(10×8) = 192 + 160 = 352 sq ft
2. Ceiling area: 12 × 10 = 120 sq ft
3. Gross area: 352 + 120 = 472 sq ft
4. Net area: 472 - 21 - 24 = 427 sq ft
5. Panels needed: 427 ÷ 32 × 1.1 = 14.7 → 15 panels
Total: 15 drywall panels needed
Common Drywall Sizes
4' × 8' Standard
32 sq ft • $6-$8
Most common size
4' × 12' Large
48 sq ft • $10-$14
Better coverage
Specialty Types
Fire-resistant, moisture-resistant
Higher cost, specific uses
Drywall Installation Tips
Add 10% waste for cuts and damaged sheets
Use larger panels to reduce joints and seams
Choose moisture-resistant for bathrooms
Consider fire-resistant for garages
Don't forget joint compound and tape
Plan for electrical outlet cutouts
Understanding Drywall Calculations
How the Calculator Works
The drywall calculator determines the net surface area by calculating wall and ceiling areas, then subtracting door and window openings. It adds any sloped wall areas and applies a waste factor to ensure you have enough material for cuts and damaged sheets.
Types of Drywall
- •Regular: Standard white gypsum board for most rooms
- •Greenboard: Water-resistant for kitchens and bathrooms
- •Type X: Fire-resistant with glass fibers
- •Soundproof: Enhanced with sound-absorbing materials
Area Calculation Formula
Net Area = Walls + Ceiling - Doors - Windows + Sloped
- Walls: 2 × (L × H) + 2 × (W × H)
- Ceiling: L × W (if included)
- Sloped: (height × base ÷ 2) × count
- Panels: Net Area ÷ Panel Area × (1 + waste%)
Pro Tip: Always order 10% extra drywall to account for waste, mistakes, and future repairs.