Construction math, made simple and free
Free Construction Tools is a growing collection of 12 free calculators and estimators for the trades — concrete, lumber, roofing, drywall, flooring, paint, tile, fencing, stairs, and more.
Why this exists
Estimating materials shouldn't mean wrestling with a spreadsheet, paying for software, or handing over your email to download a result. Whether you're a contractor pricing a job, a builder ordering a delivery, or a weekend DIYer pouring a patio, you need one thing: an honest number you can trust before you spend money.
That's the whole idea. Every tool here is free, runs entirely in your browser, and gives you a clear quantity and a rough cost — with a built-in waste factor so the estimate reflects the real world, not a perfect one.
How it's built
Each calculator uses standard, well-documented construction formulas. The math runs locally on your device — nothing you type is sent to a server or stored. Most tools support both imperial and metric units, and many let you export a clean materials list to PDF to take to the supplier or hand to a crew.
Estimates are exactly that — estimates. They're a planning aid, not a substitute for professional judgment, a supplier quote, or your local building code. Always confirm before you order or build.
Who builds it
Free Construction Tools is built and maintained by Shahzeb Zafar, an independent software developer. It's funded by unobtrusive advertising so the calculators can stay free for everyone, with no paywalls and no accounts.
Have an idea for a calculator we don't have yet, or spotted a number that looks off? That feedback is the single best way to make these tools better — get in touch.