Calculator
Wall area calculator
Calculates the area of all four walls and subtracts the area of door and window openings.
Online calculation
Enter dimensions
Result
Result
Your result will appear here after calculation.
Calculation formula
Gross wall area = 2 × (room length + room width) × room height; net wall area = gross area − door area − window area.
Example: For a 5 × 4 × 2.7 m room with one 0.9 × 2.1 m door and two 1.2 × 1.5 m windows, the net wall area is 43.11 m².
Frequently asked questions
Should I subtract doors and windows?
Yes, subtract them when estimating paint, wallpaper or plaster for the actual wall surface. Keep a practical material allowance for cutting and losses.
How should I handle niches and projections?
Measure each rectangular plane separately. Add projections and subtract niches when they are not already included in the main dimensions.