Siding calculator
Estimate outputs: Net cladding area, Area with allowance, Roof panels. Adjust Wall perimeter, Height, Openings area to match your project.
Estimate outputs: Net cladding area, Area with allowance, Roof panels. Adjust Wall perimeter, Height, Openings area to match your project.
Inputs and units
Use the units shown beside each field. Replace the sample values with your measurements and the figures on the selected product packaging.
| Parameter | Example input |
|---|---|
| Wall perimeter | 36 m |
| Height | 3 m |
| Openings area | 18 m² |
| Coverage per panel | 0.72 m² |
| Waste allowance | 10 % |
Formula and assumptions
Net cladding areamax(0, Wall perimeter × Height - Openings area)
Roof panelsceil(Net cladding area × (1 + Waste allowance / 100) / Coverage per panel)
ceil = round up; floor = round down; max = the greater value. Trigonometric angles are converted from degrees to radians.
Allowance is applied before rounding to whole packages. Whole units are rounded up; displayed decimals are rounded only for readability.
Coverage depends on the product, substrate and installation method. Enter the supplier’s consumption figures; an area estimate cannot replace a cutting layout.
Worked example
Sample values are examples, not product specifications. Run the calculation again with your own measurements.
| Result | Calculation |
|---|---|
| Net cladding area | 90 m² |
| Area with allowance | 99 m² |
| Roof panels | 138 |
Related calculators
Related tools use separate measurements. Check their inputs before transferring quantities.
These are quantity estimates. Confirm product coverage, site conditions and required dimensions before ordering.