Terms of use

By Rohit Gaur · Last updated October 30, 2026 · Report a mistake

Using this site means accepting what follows. It is written plainly, and the date at the top says when it last changed.

The calculator is free to use

There is no account, no fee and no usage limit. You may use the results for personal or commercial work — ordering materials, preparing a quote, checking someone else’s figure.

The numbers are estimates

The arithmetic is exact and tested, but it can only be as good as the measurements you give it, and material quantities depend on the layout, the product and the fitter. In particular:

• a floor area here is only as good as the measurements behind it. The whole-house calculator applies the rules of ANSI Z765 to the measurements you enter, but it does not take them: a figure for a listing, an appraisal or a loan needs measurements taken to that standard by someone who answers for them, and this site does not make a figure into one;
• a material or cost estimate is a starting point for a quote, not a quote;
• nothing here is professional, legal or financial advice.

For a measurement that must satisfy a bank, a buyer or a court, hire a qualified surveyor.

No warranty

The site is provided as it is, without warranty of any kind. To the extent the law allows, the maintainer is not liable for any loss arising from its use, including materials ordered on the strength of an estimate.

Content

The text, drawings and code are the maintainer’s work. You may quote short passages with a link back, and put the calculator or the converter on your own site with the code on the embed page. Copying whole pages is not permitted.

The research pages and their data files are the exception: they are published under CC BY 4.0, so you may reuse them, commercially too, as long as you credit SqFt Math and link to the page you took them from.

Changes

These terms may change. The date at the top says when they last did, and material changes are noted on the changelog.