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Wall Area Calculator
Compute wall area for any dimensions
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Result
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What this calculator does
Calculates net wall area after subtracting standard doors and windows, to feed paint, drywall or insulation calculations.
How to use it
- Enter wall width and height.
- Enter number of doors and windows.
- Read the net area.
Formula
grossWallArea = Width × Height netWallArea = max(0, grossWallArea − Number of Doors × 1.89 − Number of Windows × 1.44)
Formulas are shown in metric units, exactly as the calculator computes them. Imperial entries are converted to metric first. Waste is applied as a multiplier (1 + waste/100).
Areas are in m² and volumes in m³. max(0, …) prevents a negative wall area.
Variables
| Variable | Unit | Default |
|---|---|---|
| Width | m | 4 |
| Height | m | 2.5 |
| Number of Doors | - | 1 |
| Number of Windows | - | 1 |
Worked example
Using the default values of this calculator (Width = 4 m, Height = 2.5 m, Number of Doors = 1, Number of Windows = 1), the calculator returns:
grossWallArea = 4 × 2.5 netWallArea = max(0, grossWallArea − 1 × 1.89 − 1 × 1.44)
- Net Wall Area: 6.67 m²
Assumptions and limitations
- Each door is assumed 1.89 m² and each window 1.44 m²; real openings differ.
- Result cannot go below zero and has no waste margin.
Waste, rounding and buying
This is a measured area, not a purchase quantity. Use it as input to other calculators.
Frequently asked questions
- Can I use this for several walls?
- Calculate each wall separately and add the results.
- What if my windows are bigger?
- Measure them and subtract the difference by hand.