About CubedCalc

CubedCalc is a small, focused collection of calculators for construction and building projects: concrete, gravel, framing, roofing, decking, and the rest of the measurements that come up when you're planning something you're going to build. No account, no paywall, no unrelated tools bolted on for the sake of it.

Why we built this

Most general-purpose calculator sites treat construction math as one category among dozens. Finance, health, math, unit conversion, and building projects all get the same shallow treatment. We wanted a site that only does the construction and building side, and does it properly: real formulas, real worked examples, and enough explanation that you understand why the number came out the way it did, not just what it is.

The practical test we hold ourselves to is whether someone standing in a builders merchant or on a job site could use a page to make an ordering decision without needing a second source. That means showing the formula, not just the answer; stating the assumptions behind any default we have chosen; and being explicit about where a number stops being a general estimate and starts needing a professional.

What’s covered

The site currently spans five broad areas of residential and light-commercial work:

• Concrete and masonry: concrete volume and bag counts, CMU block, brick, rebar, retaining walls, and pavers.
• Aggregates and landscaping: gravel, topsoil, mulch, and asphalt.
• Framing and structure: wall framing, board feet, decks, fencing, stairs, and stair stringers.
• Roofing and exterior: roofing material, roof pitch and slope conversion, and siding.
• Interior finishes: drywall, insulation, paint, flooring, tile, and electrical wire gauge.

How we research and fact-check

CubedCalc is written and maintained by The CubedCalc Team. We are not a staff of licensed contractors, engineers, or electricians, and we don't claim to be. Every calculator is built from published references: manufacturer specs and yield data, the International Residential Code and International Building Code, NEC tables, and standard industry conventions for materials like concrete, lumber, CMU block, and brick.

Each calculator's formula is verified against a worked example before it ships, and that same worked example is published on the page so you can follow the arithmetic yourself. Some figures are a range rather than a constant. Topsoil weight swings with moisture content, and mortar coverage depends on joint size. Where that is the case we publish the range and the conditions attached to it, instead of picking one number and presenting it as fact.

Which editions we cite

Where a figure comes from a code or standard, we cite the specific section so you can check it rather than take our word for it. Unless a page says otherwise, our references are to:

• 2021 International Residential Code (IRC): stairs, guards, decks, roofing
• International Building Code (IBC): where commercial requirements differ from residential
• 2020 National Electrical Code (NFPA 70): conductor ampacity, derating, and conduit fill
• ACI 318: concrete cover and reinforcement development
• ASTM standards: material specifications such as C90 for concrete masonry units, C216 for facing brick, and C270 for mortar

Section numbers move between editions, and your jurisdiction may still be on an earlier one. Many are on the 2018 or 2015 IRC. Where we give a section number, treat it as a pointer to the right part of the code you have adopted, not a guarantee that the numbering matches.

We keep that byline honest on purpose: we'd rather tell you plainly who wrote a page than invent a fictional "licensed engineer" to make it sound more authoritative than it is. For anything structural, code-related, or safety-critical, such as stairs, wire sizing, or load-bearing work, the calculator itself says so, and you should verify the final numbers with your local building department or a licensed professional before you build.

Where we take an editorial position: waste factors

Most calculators give you a geometrically perfect number: the exact volume of the hole, the exact square footage of the wall. That number is correct and, on its own, will leave you short. Real projects lose material to over-excavation, cuts and offcuts, spillage, compaction, breakage, and pattern matching, and the loss varies enormously by material and method: a few percent on bagged concrete, considerably more on tile laid in a diagonal or herringbone pattern.

We build that allowance into the calculator output as an adjustable field rather than mentioning it as advice underneath an un-adjusted number. It defaults to a conventional figure for the material in question, and you can change it when you know your own conditions. We think a number you can actually order from is more useful than one that is technically exact, and this is the main place where our output will deliberately differ from a competitor's.

Building codes vary, and our numbers are a starting point

Code-derived figures on this site follow the model codes, primarily the IRC, IBC, and NEC. Your jurisdiction may amend any of them, and many do. Stair rise and run limits, frost depth for footings, minimum insulation R-values by climate zone, and permitted wire sizing all commonly differ from the model code at the local level.

Pages that lean on code carry a stronger disclaimer than the rest of the site, and the electrical and structural pages carry a stronger one still. Treat those numbers as a way to arrive at your local building department already understanding the question, not as a substitute for asking it.

What this site is not for

CubedCalc estimates quantities. It does not perform structural engineering, size load-bearing members for a specific set of loads, or produce anything you should submit for a permit. Nothing here accounts for soil conditions, seismic or wind loading, live loads, or the interaction between assemblies. If a mistake in the number could cause something to fall down, injure someone, or fail an inspection, the calculator is the wrong last step. A licensed professional is the right one.

How the calculators work

Every calculator on this site runs in your browser, using the same formulas laid out in the article next to it. Nothing is hidden behind an API call or an embedded widget from somewhere else. If you want to check our math by hand, the page shows you how. We don't collect the dimensions you type in; the arithmetic happens on your device and stays there.

How this site is funded

CubedCalc is supported by display advertising. We don't run an affiliate program or accept payment to feature a product or supplier. No supplier, manufacturer, or brand has any input into the figures we publish or the defaults we choose. See our Privacy Policy for details on how advertising and analytics cookies are used.

Questions or corrections

Found a calculator that doesn't match your local code, or a number that looks off? Email us at contact@cubedcalc.com or visit the Contact page. We fact-check every calculator, but building codes and material specs vary by region and change over time, and reports from people using them on real job sites are how we catch mistakes. Corrections are made to the page directly rather than logged in an errata list, so what you see is always the current figure.