HomeCalcUSA calculators follow one method, applied consistently across all 39 tools:
- Formula first. Every calculator page states its formula in plain text, before or beside the tool, with units and the meaning of each input.
- Your inputs, not our prices. Prices, densities, coverages, rates and product yields are entered by you or labelled as illustrative defaults in the form. No county fee database, national price table or market dataset is claimed.
- Worked examples that reproduce. Each calculator page includes at least one worked example, and a “Load worked example” button fills the form with that example’s inputs so you can verify the result yourself.
- Rounding at the right step. Money is shown to cents. Monthly mortgage interest is rounded to cents in the schedule and the final payment is capped so the balance ends at $0. Geometric values keep full precision until a purchasable unit (box, bag, bundle, pail, pack, sheet, load, brick, block or board) is rounded up — never before.
- Local calculation. Calculator arithmetic runs in the visitor’s browser. The calculators make no network request and put no entered values into the page address.
- Limits stated, not hidden. Each page lists what the tool does not do: no loan approval, no appraisal, no structural design, no final equipment selection, no code compliance ruling. Where a specialist decision is needed, the page says so.
- US conventions. US short tons (not metric tonnes), US modular brick and block modules (including joints), nominal versus actual lumber dimensions kept distinct, and mills versus percent kept distinct for property tax.
What is not modelled
Adjustable-rate mortgages, FHA/VA/USDA program engines, APR computation from note rate plus fees, automated home valuation, structural design, duct design, excavation safety design and code compliance checks are all out of scope for the current tools. The automated valuation project is deferred entirely until a licensed data source, coverage checks and address-privacy controls exist; the home-equity tool instead accepts a value you enter.
Review and correction
Content is checked against its stated formula and worked example before publication. Errors reported by readers are reproduced, corrected and logged. No licensed professional review is claimed unless a real review has been commissioned and is named on the relevant page — see the Editorial Policy.