About HomeProjectCalcs

HomeProjectCalcs is an independent collection of material-estimation calculators for DIY home projects, built and maintained by a small web publisher based in Spain. It exists because the question behind most weekend projects — how much do I actually need to buy? — is usually answered by either a forum guess or a calculator that hides its math. We think you deserve the formula, the constants, and a worked example you can check by hand.

The company that publishes this site is identified in our privacy policy.

How the formulas are sourced

Calculators combine dimensional arithmetic with stated material assumptions: bag yields printed on concrete sacks (an 80 lb bag yields 0.60 ft³), standard sheet and roll coverages, on-center framing conventions, and published rule-of-thumb rates for consumables like joint compound and screws. Where a number genuinely varies — pallet coverage, soil weight, paint coverage on porous walls — check the assumption against your product label or supplier. Adjustable fields let you use your own figures where supported. Pages with reference links distinguish product guidance from the geometric calculation. Allowances and rounding are explained alongside the result.

What we don’t do

We don’t state prices as facts (they change weekly and by region), we don’t invent fake reviewer personas, and we don’t pad pages with filler. Every page is a calculator, its formula, one worked example, a reference table, and answers to the questions people actually ask — nothing else.

Found an error?

Calculators are code, and code has bugs. If a result looks wrong, a constant seems off, or a worked example doesn’t match what the tool shows, please tell us via the contact page. Error reports get priority over everything else we do, and we investigate reproducible problems before adding new tools. Estimates remain estimates, though — always confirm final quantities with your supplier and local building code before you buy or build.