About BuildFigure

BuildFigure is a small, independent project maintained by one person.

I’m not a contractor — I’m a DIYer. I paint my own rooms, spread my own mulch, build decks, plant trees, frame rooms, and fix my own appliances rather than calling someone. Every one of those jobs starts with the same annoying question: how much of this do I actually need to buy? The calculators I found handed me a number with no explanation, so I built the one I wanted.

I’m also a software engineer, which shapes how I built it. Instead of asking you to trust credentials I don’t have, I publish the math — every formula, constant and assumption, where each number comes from, and a dated log of every correction.

Where I haven’t done the work myself, I say so

I’ve never poured a slab. The concrete figures here come from Quikrete’s and Sakrete’s published bag yields — 0.30 cu ft for a 40 lb bag, 0.45 cu ft for a 60 lb bag, and 0.60 cu ft for an 80 lb bag, which is where the familiar 90 / 60 / 45 bags-per-cubic-yard figures come from. You can check every one against the bag you’re holding or the manufacturer’s own published yield.

What’s here

A set of free material calculators — concrete, paint, drywall, gravel, mulch, topsoil and flooring — that convert your measurements, apply a stated waste factor, and round up to whole purchasable units (bags, sheets, yards or gallons). Each result shows how it was reached, and the assumptions it used, so you can disagree with a number rather than just accept it.

Alongside them is a library of plain-English guides on how to estimate a project, why real-world numbers vary, and the mistakes that cost people a second trip to the supplier.

How it stays free

BuildFigure is supported by advertising and affiliate links. That never affects your price or the numbers the calculators produce. The details are in the Affiliate & Advertising Disclosure, Privacy Policy, and Terms of Use.

Corrections

If a number here is wrong, I want to know. Email hello@buildfigure.com or use the contact page, and include the calculator and the inputs you used so I can reproduce it. Fixes get logged, with dates, on the changelog. These estimates are for planning — confirm quantities with your supplier before you order.