Disclaimer

Last updated: 30 October 2026

Estimates, not guarantees

The arithmetic on each page is exact for the formula shown, and every page displays that formula. What the arithmetic cannot account for is the physical world: subgrade that is out of level, a supplier whose bag yield differs from the printed figure, a plan that calls for a thickened edge, or a delivery that arrives short. Results are a starting point for planning and ordering, not a specification.

Not professional advice

Nothing here is engineering, legal, tax, or financial advice, and using the site does not create any professional relationship. Structural quantities — footing sizes, rebar spacing, slab thickness, beam spans — are governed by your local building code and by a design professional's judgement about your site. Tax results depend on facts about your return that a calculator cannot see. Before you act on a number that carries money or safety consequences, have it reviewed by a licensed professional in your jurisdiction.

No warranty, and limits on liability

The site and its calculators are provided “as is”, without warranty of any kind, express or implied, including fitness for a particular purpose. To the fullest extent permitted by law, FigureMill is not liable for any loss, cost, or damage arising from use of the site, including wasted material, project delays, incorrect filings, penalties, or interest. You use the results at your own risk.

How to check a result before you rely on it

• Compare against the worked example. Every page includes one with real numbers. If your figure is far off it, check your units first — inches entered as feet is the most common error.
• Confirm the constant. Where a figure changes annually (a tax wage base, a bag yield, a price range), the page names the value it uses. Check that value against the issuing source.
• Add your own waste and contingency. Concrete needs 5% to 10% extra; framing lumber needs 10% to 15%. The calculators keep waste as a separate, visible number rather than hiding it in the result.
• Verify against code. For anything structural, the authority is your local building department and the adopted code edition, not a web page.

Advertising and affiliate links

This site is supported by display advertising. Advertisements are served by third parties and are marked “Advertisement” in the page layout. Advertising never influences a formula, a default value, or a result. Where a page links to a retailer, that link may be an affiliate link, which can earn the site a commission at no cost to you; such links never change the price you pay and never determine which products a page discusses.

External links

Pages cite outside sources — manufacturer packaging, IRS publications, ACI provisions, state revenue departments — so you can verify a figure. Those sites are outside our control and we are not responsible for their content or for changes they make after we cite them.

Corrections

If you find an error, please tell us and include the page and the figure you believe is wrong. Corrections are logged on the methodology page along with the date the page was last reviewed.