Wall Area Calculator
Wall Area Calculator
Calculate the total wall surface area for your painting, wallpaper, or tiling project. Accounts for room dimensions and subtracts doors and windows for accurate coverage estimates.
What This Calculator Includes:
- Room dimensions: length and width (feet)
- Wall height: ceiling height (feet)
- Door and window area: optional deduction for openings
- Accurate surface area: total paintable/coverable wall space
Wall Area Formula:
Wall Area = 2 × (length + width) × height − doors & windows
Example: 12×10 ft room with 8 ft ceilings = 2 × (12 + 10) × 8 = 352 sq ft of wall space
Common Applications:
- Interior painting: calculate paint gallons needed
- Wallpaper projects: determine rolls required
- Wall tile installation: bathroom, kitchen, accent walls
- Wainscoting & paneling: partial wall coverage
- Renovation planning: material estimation and budgeting
Professional Tips:
- Paint coverage: 1 gallon covers ~350-400 sq ft (1 coat)
- Primer requirements: new drywall or color changes need primer
- Multiple coats: multiply wall area by number of coats needed
- Textured surfaces: may require 10-20% more paint
Standard Door & Window Sizes:
- Interior door: ~20 sq ft (32\" × 80\")
- Exterior door: ~21 sq ft (36\" × 80\")
- Standard window: ~15 sq ft (3' × 5')
- Large window: ~24 sq ft (4' × 6')
Material Estimations:
- Paint: 1 gallon per 350-400 sq ft
- Primer: 1 gallon per 300-350 sq ft
- Wallpaper: varies by pattern and width
- Wall tile: depends on tile size and pattern
Frequently Asked Questions
How do I calculate wall area for painting?
Use the formula: 2 × (length + width) × height. Subtract door and window areas for accuracy. A 12×10 ft room with 8 ft ceilings has 352 sq ft of wall area.
Should I subtract doors and windows from wall area?
Yes, for painting and wallpaper. You don't paint doors/windows, so subtracting saves money. For planning purposes, some contractors include them for simplicity.
How much paint do I need per square foot?
One gallon covers 350-400 sq ft typically. For total paint needed: wall area ÷ 350, then multiply by number of coats required.
Do I need primer for my painting project?
Yes for new drywall, dramatic color changes, or stained surfaces. Primer typically covers 300-350 sq ft per gallon.
How do I handle irregular room shapes?
This calculator works for rectangular rooms. For L-shaped rooms, calculate each section separately and add the totals together.
What if my walls have texture?
Textured walls (orange peel, knockdown) use 10-20% more paint than smooth walls. Order extra paint for heavily textured surfaces.