About InsulationCalcs
InsulationCalcs is an independent project with one goal: to gather the everyday calculations homeowners, DIYers and small contractors reach for when insulation is going in — R-value & quantity, cost estimators, spray foam, attic & roof, wall/floor/crawlspace/basement, and materials & savings — in one focused, free, no-signup hub with transparent formulas, so you can budget an insulation project 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 insulation contractor, a building-science professional, a certified energy auditor 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). That training covers the R-value/U-value physics directly — the electrical-thermal analogy: thermal resistances add in series like resistors, heat flow is like current and U = 1/R is like conductance — so the arithmetic of these calculators is squarely in my competence, while insulation-contractor judgement (installation quality, code, fire/vapor detailing) is explicitly deferred to licensed pros and product data sheets.
Our principle: transparent & durably correct
Every calculator shows its formula, a worked example and a reference table. The tools rest only on timeless building physics (R = Σ thickness × R/inch; U = 1/R; required thickness = target R ÷ R/inch; bags = ceil(area ÷ coverage); board-feet = area × thickness; sheets = ceil(area ÷ 32); cost = quantity × your $/unit + labor + add-ons, ×(1 + contingency)) and stable, labeled conventions (R/inch by material, IECC climate-zone target R, coverage-per-bag, batt coverage, set yields, waste %). 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 material-quantity / R-value guides: get itemized written quotes from licensed, insured insulation contractors, confirm coverage-per-bag, R/inch and set yield against the exact product, and order a little extra (~5–10%) for framing, gaps and settling. Fire-rating, engineered vapor-barrier design, HVAC sizing and whole-house energy audits are out of scope and are for the product data sheet, local code and a certified professional. Questions? Use the contact page.