Wall Area Calculator
Calculate paintable or clad wall area excluding doors and windows.
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What this tool does
Calculate paintable or clad wall area excluding doors and windows. Enter the sum of wall lengths; do not enter room floor area.
How to use the Wall Area Calculator
- Enter or select total wall length in ft.
- Enter or select wall height in ft.
- Enter or select total opening area in sqft.
- Read the calculated result; change any measurement to compare alternatives.
Formula
net wall area=max(0,length×height−openings)
- length
- Total wall length (ft, before metric conversion)
- height
- Wall height (ft, before metric conversion)
- openings
- Total opening area (sqft, before metric conversion)
Enter the sum of wall lengths; do not enter room floor area.
Worked example
For wall area calculator, the following measurements illustrate the exact method: Total wall length: 64; Wall height: 8; Total opening area: 40.
Inputs
- Total wall length64 ft
- Wall height8 ft
- Total opening area40 sq ft
Result
- Net wall area472 sq ft
- Gross wall area512 sq ft
Results explained
- Net wall area
- Net wall area from the formula above, expressed in sqft before metric conversion. Enter the sum of wall lengths; do not enter room floor area.
- Gross wall area
- Gross wall area from the formula above, expressed in sqft before metric conversion. Enter the sum of wall lengths; do not enter room floor area.
Frequently asked questions
Total wall length times height minus opening area gives the net surface.
Measure wall lengths, height and the combined area of openings.
Use 5–10% for simple layouts and 10–15% for diagonal cuts or complicated outlines; the allowance is editable.
Split the outline into rectangles or triangles and calculate each section separately. Do not count overlapping sections twice.
This is a purchasing estimate, not a structural design. Confirm measurements and local requirements before buying or building.