How this calculator works
Net wall area = length x height (single face, when width is 0) or 2 x (length + width) x height (full room perimeter) - opening area. Panels = round up[(net area x waste factor) / coverage per panel].
Worked example
A single 10 m x 2.5 m wall face with two windows has 25 m2 gross and 22.2 m2 net; with 10% waste (24.42 m2) at 0.9 m2 per board, that is 28 boards.
Assumptions to check
- "Siding" (US) and "cladding" (UK) describe the same exterior wall covering; only the local name differs.
- Fire rating, weather-exposure suitability, and fixing/batten systems are out of scope - a code/product-selection question, not a material-quantity one.
- Coverage per panel/board should come from the manufacturer datasheet, since profile overlap varies by product.