About DIYCalcs

DIYCalcs is a free collection of material calculators for home-improvement and construction projects. The goal is simple: help homeowners and DIYers buy the right amount of material the first time, so projects stay on budget and fewer half-used cans and offcuts end up in landfill.

How our calculators work

Every tool runs entirely in your browser using standard, published figures — manufacturer coverage rates for paint and flooring, industry waste factors for tile and cut materials, and standard bag yields for concrete and aggregates. Nothing you type is sent to a server or stored. The numbers are reference estimates for planning; for structural work, or any large order, confirm quantities with your supplier or a licensed contractor before buying.

Where our figures come from

We base coverage and waste figures on commonly published manufacturer specifications and the conventions contractors use day to day: roughly 350 sq ft per gallon for smooth interior wall paint, a 10% waste allowance for straight-laid tile and flooring (rising to 15–20% for diagonal and herringbone patterns), and bag yields of about 0.60, 0.45 and 0.30 cubic feet for 80, 60 and 40 lb concrete bags. Where a figure varies by surface or product, we let you change it in the calculator.

Independence

DIYCalcs is reader-supported through advertising. Ads are clearly labelled and never influence the calculations, which are based purely on measurement and material specifications. We do not collect personal data to run the tools.

Contact

Spotted an error or want a calculator we don't have yet? We'd like to hear about it — see the contact page.