Terms of Use

Use the numbers, check the numbers. These calculators are a planning aid, not construction documents.

Last updated: 11 August 2026

Using this site

MaterialsMath is free to use. Take the results, use them, order your materials from them. You do not need our permission and you do not owe us anything.

What you may not do is scrape the site wholesale to republish it, or copy the written guidance as your own. The calculators exist so people can plan their own work.

The important part: these are estimates

Every quantity on this site is an estimate produced from the numbers you typed and the assumptions listed on each page. Those assumptions are published in full, on every calculator, precisely so you can check whether they apply to your job.

They are not construction documents, and they do not replace:

• your local building code, which sets the spans, spacings and clearances that actually govern the work;
• a licensed engineer, where the work is structural;
• your building official, who has the final word on what is permitted where you live;
• the manufacturer's instructions for the specific product you bought, which override any general figure we publish.

Where a manufacturer's coverage chart disagrees with a calculator on this site, the manufacturer is right. We say so on the pages where it comes up.

What we do not warrant

We check our arithmetic, publish our formulas, and cite where our figures come from. We still cannot promise that a result is correct for your particular job, because we cannot see your job.

To the extent the law allows, MaterialsMath is provided as-is, without warranty of any kind. We are not liable for material ordered in the wrong quantity, work that has to be redone, or any other loss arising from use of this site. If a number here looks wrong to you, it may well be — measure again, check the assumptions, and tell us at hello@materialsmath.com so we can fix it.

Safety

Building work involves tools, dust, heights and loads. Nothing on this site is a substitute for knowing how to use the tool in your hand safely. Structural work in particular — anything holding a floor, a roof or a wall up — belongs to people qualified to do it.

Advertising

This site is funded by display advertising. Advertisers do not choose, review or influence anything we publish, and a product appearing in an ad on this site is not a recommendation from us.

Links out

We link to manufacturers, standards bodies and other references where it helps. We do not control those sites and are not responsible for what they say.

Changes

We update these terms when something real changes. The date at the top tells you when that last happened.