Terms of Use
Last updated: 11 September 2026
These terms apply to your use of concretemaths.com.au (the "site"), operated by ConcreteMaths ("we", "us"). By using the site you accept them. If you do not accept them, please do not use the site.
The short version
The calculators give you an estimate of quantity. They do not design anything, they are not engineering advice, and you should confirm the numbers with your supplier, builder or engineer before you spend money.
What the site does
The site provides free calculators that estimate volumes of concrete and related quantities from dimensions you enter. Everything runs in your browser. There is no account to create and nothing to buy.
Estimates only
Every result is an estimate based solely on the numbers you type in. We do not know your site, your ground conditions, your formwork, your wastage, your supplier's mix or their delivery increments. Real jobs differ from arithmetic.
In particular, bag-count estimates depend on the yield of the specific product you buy. Yields differ between products of the same weight. The figure printed on the bag always takes precedence over ours.
Not engineering or construction advice
This is the most important term on this page. The calculators estimate how much, never whether it is adequate. They do not tell you what thickness a slab should be, what reinforcement it needs, what strength class or exposure class to specify, how a footing should be sized, or whether any of it complies with the National Construction Code, the relevant Australian Standards, or your local requirements.
Those questions depend on loading, soil, drainage, climate and use, and they need someone who can assess your site and take professional responsibility for the answer — your concreter, your builder, or a structural engineer. Do not treat anything on this site as a substitute for that.
No warranty
We have tried hard to make the arithmetic and unit conversions correct, and the calculators are checked against worked examples. Even so, the site is provided "as is" and "as available", without warranties of any kind, whether express or implied, including any implied warranty of accuracy, merchantability or fitness for a particular purpose.
We do not warrant that the site will be uninterrupted, error-free, or that any result is accurate for your situation.
Limitation of liability
To the maximum extent permitted by law, we are not liable for any loss or damage arising from your use of the site or reliance on any result it produces — including over-ordering, under-ordering, wasted material, wasted labour, delay, rework, or any indirect or consequential loss.
Nothing in these terms excludes, restricts or modifies any guarantee, right or remedy you have under the Australian Consumer Law that cannot lawfully be excluded. Where our liability cannot be excluded but can be limited, our liability is limited to re-supplying the relevant service, which for a free site means providing access to it again.
Your responsibilities
- Check that the figures you enter are the figures you meant, and that the units are the ones you intended.
- Confirm final quantities and specifications with your supplier, builder or engineer before ordering.
- Do not use the site in any way that damages it, interferes with anyone else's use of it, or breaks the law.
If you find a mistake
Please tell us. Corrections to the calculations are the most useful message you can send, and they get fixed quickly.
Intellectual property
The text, design and code of the site belong to us. You are welcome to use the calculators, link to any page, and share your results. You may not republish the site's content as your own.
Links to other sites
Where we link to another site, we do so because we think it is useful. We do not control those sites and are not responsible for their content or their handling of your information.
Privacy
How we handle information is set out in the privacy policy.
Changes
We may update these terms as the site changes. We will revise the "last updated" date above when we do. Continuing to use the site after a change means you accept the revised terms.
Governing law
These terms are governed by the laws of Victoria, Australia, and you and we submit to the courts of that jurisdiction.
Contact
ConcreteMaths
hello@concretemaths.com.au
Victoria, Australia