About SidingCalcs
SidingCalcs is an independent project with one goal: to gather the everyday calculations homeowners, DIYers and small siding contractors reach for when a house gets new siding or a re-side — siding quantity & material, installation cost estimators, cost by material, whole-house & project cost, trim, soffit & specialty siding, and siding selection & planning — in one focused, free, no-signup hub with transparent formulas, so you can budget a siding job and sanity-check a contractor’s quote.
Who is behind it
Author and curator
To be clear about credentials: I am the author and curator of this site — not a licensed siding contractor, an installer or any trade professional, and I claim no trade credential. What I bring is relevant and real: building deterministic online calculators (open-source Python projects) and electronic-engineering training (Systems Theory, Sapienza University of Rome). Siding quantity is plane geometry (siding area = wall perimeter × height + gables (½ × base × height) − openings; squares = area ÷ 100; boxes = area ÷ coverage) and siding cost is a quantity × unit-price sum (cost = area × $/sq ft or squares × $/square + labor + add-ons) — the same rigorous arithmetic I apply in systems and electronics, so the math of these calculators is squarely in my competence, while moisture/flashing/adhesion judgement, structural sheathing, pre-1978 lead-safe abatement and code compliance are explicitly deferred to licensed pros, the EPA RRP rule and the manufacturer’s installation instructions.
Our principle: transparent & durably correct
Every calculator shows its formula, a worked example and a reference table. The tools rest only on timeless wall/gable-area geometry (wall area = perimeter × height; gable = ½ × base × height; net area = gross − openings; squares = ceil(area × (1 + waste) ÷ 100); boxes = ceil(area × (1 + waste) ÷ coverage); cost = area × your $/sq ft + labor + add-ons, ×(1 + contingency)) and stable, labeled conventions (coverage & exposure per square by material, waste factor by layout, door/window/garage deductions, cost bands, lifespan). There are deliberately no live material or labor prices, no regional cost indexes, no product catalog and no contractor directory — cost tools use the prices you enter — so the results stay valid over time.
Correctness is checked against known reference values (see the methodology and the numeric self-check). The formulas and their basis are documented under Sources & formulas. All results are planning estimates and siding quantity / material guides: get itemized written quotes from licensed, insured siding contractors, measure your actual walls and gables and follow the manufacturer’s exposure and installation instructions, and allow extra for waste, trim and complex layouts. Professional moisture/flashing judgement, structural repairs, lead-paint abatement and code compliance are out of scope and are for the EPA RRP rule, local code and a certified professional. Questions? Use the contact page.