About RestorationCalcs
RestorationCalcs is an independent project with one goal: to gather the everyday calculations homeowners, landlords and buyers reach for after a disaster — water & flood damage, mold remediation, fire & smoke, sewage & biohazard, radon/asbestos/lead, and air-duct & indoor-air-quality — in one focused, free, no-signup hub with transparent formulas, so you can budget a project and sanity-check a restoration 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 an IICRC-certified restoration technician, industrial hygienist, certified mold assessor, NRPP/NRSB radon professional, licensed asbestos/lead abatement contractor, physician, insurance adjuster or attorney. What I bring is relevant and real: building deterministic online calculators (open-source Python projects) and engineering training, i.e. rigor on the arithmetic and sizing math. That is what it takes to curate a hub of calculators: transparent method, correct formulas, cited conventions and worked examples.
Our principle: transparent & durably correct
Every calculator shows its formula, a worked example and a reference table. The tools rest only on timeless restoration math (restoration cost = affected sq ft × your $/sq ft × category/severity multiplier + line items, ×(1 + contingency); air movers = ceil(sq ft ÷ coverage); dehumidifiers = ceil(sq ft ÷ LGR coverage); ACH = CFM × 60 ÷ volume; insurance out-of-pocket = max(0, min(covered, damage) − deductible)) and stable conventions (IICRC water Category/Class; EPA mold 10-sq-ft threshold and radon 4 pCi/L action level; 27 cu ft per cu yd; labeled air-mover and dehumidifier sizing typicals). There are deliberately no restoration or labor prices, no regional cost indexes 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 equipment-sizing typicals: get itemized written quotes from licensed, insured, IICRC-certified restoration contractors; Category 2/3 water, sewage and biohazard are health hazards — hire certified pros and do not DIY Category 3; mold over ~10 sq ft usually needs a pro (EPA); radon is a health risk (EPA 4 pCi/L); asbestos and lead are regulated (licensed abatement only); the insurance tool is illustrative only. Questions? Use the contact page.