About Us
Free, accurate estimating tools for masonry and concrete work
ConcreteBlockCalculators builds free online calculators for people who work with concrete block and concrete — contractors, masons, landscapers, builders’ merchants, and homeowners taking on their own projects.
We started with a simple frustration: most online material calculators show you a number and nothing else. No formula, no assumptions, no way to check whether the answer is sensible before you place an order. If the number is wrong, you either run short mid-build or pay for material you don’t need.
We built these tools to work the other way round.
What makes our calculators different
We show the working. Every result displays the raw calculation and the waste allowance separately, so you can see exactly how the number was reached. The formulas and assumptions behind each tool are published on the page — concrete density, bag yields, block face areas, gravel factors. Nothing is hidden inside a black box.
We draw your project. Each calculator produces a scale drawing that redraws as you type. The block calculator draws the wall elevation in running bond with the real course count. The retaining wall calculator draws the section with your chosen batter. The fire pit calculator draws the plan view of your ring. It is the fastest way to catch a mistyped dimension — a wall that should be five courses but draws fifteen is obvious immediately, in a way a number alone never is.
We verify against real figures. Our formulas are checked against published worked examples and standard trade rates, not estimated. Where a constant is an industry assumption rather than a published standard, we say so on the page.
Nothing is collected. The calculators run entirely in your browser. No sign-up, no account, no data sent anywhere. Your project details stay on your device.
Our tools
- Concrete Block Calculator (CMU) — blocks, mortar, sand, horizontal reinforcement, grout and lightweight fill for a block wall
- Retaining Wall Calculator — blocks, cap blocks, base gravel, drainage backfill, landscape fabric and geogrid, with setback and batter
- Concrete Block Weight Calculator — weight per block and total in pounds, kilograms and tons, plus pallet counts and vehicle transport guidance
- Fire Pit & Planter Calculator — blocks, cap stones, gravel base, fire ring sizing and planting soil for circular, square and rectangular builds
- Concrete Slab Calculator — cubic yards, bag counts, slab weight, rebar or mesh, gravel base, excavation and installed cost range
Every tool is free, needs no registration, and works on phones as well as desktops — because most of the time you are standing on the job, not sitting at a desk.
A word on responsibility
Our calculators produce planning estimates. They are a starting point for ordering material and budgeting a job, not a substitute for professional judgement.
Masonry and concrete work is structural. Local building codes, soil conditions, drainage, climate, and load requirements all affect what you should actually build. Confirm quantities with your supplier before ordering, and consult a licensed engineer or contractor for structural work — including any retaining wall over four feet, foundation slabs, and load-bearing walls.
We would rather be useful and honest about our limits than overstate what a web page can tell you.
Get in touch
Found an error in a formula, or want a calculator we do not have yet? We would genuinely like to hear about it. Email us at concreteblockcalculators@gmail.com