Terms of Use & Estimation Disclaimer

Last updated: October 22, 2026

These terms govern your use of CalcWorks (getcalcworks.com). They are written in plain language on purpose: this site gives you free estimating tools, and in return we ask you to use them as what they are — planning aids — and to read the limits below before you buy materials or build anything based on a result.

What this site is, and accepting these terms

CalcWorks is a free collection of online calculators for construction and home-improvement projects. Each calculator applies a standard formula or published table to the numbers you enter, and every calculator page shows the formula, a worked example and its sources so you can check the arithmetic yourself. By using this site you accept these terms. If you do not agree with them, please do not use the site.

Estimates are planning guides only

Every result on this site is an estimate, produced from standard formulas, published reference data and the measurements you type in. Results are planning guides for budgeting, comparing options and preparing shopping lists. They are not professional architectural, engineering, surveying or contracting advice, and they are not a guarantee of the quantities any particular job will need. Real projects vary: material sizes and densities differ by supplier and region, sites are rarely perfectly square or level, cuts and breakage consume material, and methods differ between builders.

Before ordering materials or starting work, verify the quantities for your project with your supplier or contractor, and follow your local building codes, permit requirements and safety rules. Structural decisions — slab thickness and reinforcement, footing sizes, roof and floor loads, retaining walls, electrical and plumbing work — belong to your local code and a licensed professional, not to a calculator.

Accuracy

We build each calculator from the formula or published table the trade itself uses, name the source on the page, and test every figure against hand-worked examples before publishing. When we find an error, or a reader reports one that checks out, we fix it. That said, we cannot promise that every result is exact for every situation: a formula is only as good as the measurements fed into it and the assumptions listed on its page. Treat results as a well-checked starting point, and apply the waste allowances and professional checks appropriate to your job.

No warranty

This site and its calculators are provided “as is” and “as available”, without warranties of any kind, whether express or implied — including any implied warranty that the site will be error-free, uninterrupted, or fit for a particular project or purpose.

Limitation of liability

Decisions made from an estimate — materials ordered, money spent, work started, altered or demolished — are yours. To the fullest extent permitted by law, CalcWorks and the people who run it are not liable for losses arising from the use of, or inability to use, this site or its results, including over- or under-ordering of materials, project delays, rework, or damage to property. If you are unsure about a quantity, a contractor's check is far cheaper than a second delivery — or a second slab.

Acceptable use

You may use the calculators freely for your own projects, personal or commercial. You may not misuse the site: do not attempt to disrupt, overload or gain unauthorized access to it, do not scrape or copy it in bulk by automated means, and do not use it for anything unlawful. Linking to any page is welcome; presenting the site's content as your own work is not.

External links

Pages may link to outside sources — standards bodies, manufacturers' data sheets and reference publications — so you can verify our method. Those sites are run by others; we are not responsible for their content, availability or privacy practices, and a link is a citation, not an endorsement of everything on the linked site.

Changes to these terms

If these terms change, the updated version will be posted on this page with a new date at the top. Continuing to use the site after a change means you accept the updated terms.

Contact

Questions about these terms, or about how a calculator reaches its numbers: email hello@getcalcworks.com or use the contact page.