Terms of Use

You may use these calculators freely for personal and commercial projects. You may not scrape, mirror or republish the calculators, data files or written content without written permission.

Everything here is provided as-is. We make no guarantee that a result is accurate for your specific building, climate or code jurisdiction.

We are not liable for material shortfalls, overbuying, construction defects, code violations or any other loss arising from use of this site. The maximum liability is zero dollars, which is also what you paid.

We may update these terms or any calculator formula at any time. Continued use after a change means you accept it.