About Concrete Quantity
Concrete Quantity is a free online resource for working out how much concrete you need for DIY and building projects.
We build precise, easy to use concrete calculators covering slabs, footings, walls, columns, post holes, circular slabs, stairs and more. Every result includes cubic yards, cubic metres, bag counts, truck loads and cost estimates, in imperial or metric units.
Our approach is simple: accurate maths, honest estimates, and transparent methods. Each calculator shows the formula it uses, so you can check the working yourself. Bag yields follow manufacturer specifications, and our volume calculations use standard geometric formulas.
A note on who we are: we are tool builders, not contractors. We do not claim decades of pouring experience, and we do not review concrete brands we have not tested. What we do is check our maths carefully and cite our sources, so you can trust the numbers.
If you spot an error, or you would like a calculator we do not have yet, email us at ellenstevensone@gmail.com. We read every message.
Last updated: October 2026.