Settings
White ThemeInputs use the selected unit. Outputs show ft² and m².
Set to 0% to disable. Applies after opening deductions.
Tip: For gable ends select Triangle. For knee walls use Trapezoid.
Walls
Rect / Triangle / Trapezoid
| # | Shape | Length (ft) | Height (ft) | Length B (ft) | Qty | Area (ft²) |
|---|
Rectangle: area = length × height. Triangle: 0.5 × base × height. Trapezoid: height × (a + b) ÷ 2.
Openings (subtract)
| # | Width (ft) | Height (ft) | Qty | Area (ft²) |
|---|
Walls Area
0.00 ft²
0.00 m²
Openings Area
0.00 ft²
0.00 m²
Net Area
0.00 ft²
0.00 m²
With Waste
0.00 ft²
0.00 m²
Formulas Used
- Rectangle: Area = Length × Height
- Triangle (gable): Area = 0.5 × Base × Height
- Trapezoid: Area = Height × (Top + Bottom) ÷ 2
- Totals: Net Area = Σ(Wall Areas) − Σ(Opening Areas)
- Waste: With Waste = Net Area × (1 + Waste%)
- Unit Conversion: 1 ft = 0.3048 m; 1 ft² = 0.092903 m²
Roundings are cosmetic; computations use full precision, then rounded for display.
How to Use
- Select the input Units and set a Waste percentage.
- Click Add Wall to insert rows. Choose a Shape per row.
- Enter dimensions and Quantity. Lengths follow the selected unit.
- Add Openings for doors or windows. Quantities are supported.
- Totals update live. Adjust Rounding for reporting preferences.
- Use Download CSV or Download PDF to export.
- Click Load Example any time to see a realistic scenario.
Example Data Table
| Type | Shape | Length A | Height | Length B | Qty | Area (ft²) |
|---|---|---|---|---|---|---|
| Wall | Rectangle | 20 ft | 9 ft | — | 2 | 360 |
| Wall | Triangle | 15 ft | 4 ft | — | 1 | 30 |
| Wall | Trapezoid | Top 10 ft | 8 ft | Bottom 14 ft | 1 | 96 |
| Opening | — | 3 ft | 4 ft | — | 4 | 48 |
| Opening | — | 3 ft | 7 ft | — | 2 | 42 |
| Example Net Area | 396 ft² | |||||
This example matches what the Load Example button inserts into the calculator.
FAQs
Measure the visible wall surface you intend to cover. If a soffit or bulkhead lowers the height, use the reduced height for that section or split into separate rows.
Choose Triangle for simple gables and enter base and rise. For sloped knee walls, use Trapezoid with top and bottom lengths and vertical height.
Typically no. Their areas are small and covered by your waste. Subtract larger items like doors, picture windows, and oversized niches.
Yes. Select Meters for inputs. The calculator converts and displays both square feet and square meters automatically.
Calculations use full precision. You can adjust rounding to match how you report or order materials.
This tool focuses on area. Use the exported numbers in a paint coverage or sheet count calculator for material-specific estimates.
Split complex walls into multiple rows by shape. For example, enter the rectangular portion as one row and the triangular gable as another, then subtract openings.