About CalcTheBuild

CalcTheBuild makes free, fast and transparent construction calculators. Whether you're a contractor pricing a job, a self-builder planning an extension or a homeowner tackling a weekend project, our tools turn measurements into quantities and costs you can take to a supplier.

What we believe

• Show the working. Every calculator explains its formula and assumptions, so you can check the numbers yourself.
• Work the way you do. Imperial and metric units, regional material sizes and local currencies are built in, so builders in the US, UK, Canada, Australia and New Zealand all get relevant answers.
• Free and private. No sign-up, and the numbers you enter stay in your browser.

How our calculators are built

Our formulas are based on standard industry practice and manufacturer data, including published brick dimensions, product yields for bagged concrete and mortar, and typical coverage rates for paint, drywall and roofing materials. Default prices are typical national averages and should be replaced with your local quotes.

Important note

Our calculators are estimating tools, not engineering advice. For structural work, foundations and anything covered by building codes, always consult a licensed engineer, architect or contractor.

Have a suggestion or found an error? Get in touch. We read every message.