About BuildersCalcs

What is BuildersCalcs?

It is a material quantity site. You give a calculator the size of the job, and it tells you how much to buy, in the units the product is sold in: bags, boxes, sheets, bundles, rolls, boards or cubic yards and cubic metres. Each result comes with the working shown step by step, so you can check it against a quote or a supplier's figure.

Around the calculators sit guides on measuring a job before you order, reference tables such as mix ratios and tile sizes, and comparisons of materials that do the same job. Every page is free to use. There is no account, no sign-up and no limit. Start from the full calculator directory, or use the full site map to see every page at once.

Who is it for?

Mainly people doing their own work at home: a patio, a floor, a fence, a room to paint. Tradespeople and estimators checking a takeoff are the second audience, and the worked steps are written so they can be checked quickly.

The site serves readers in the US and in the UK and Europe. Every calculator has a US/metric switch. It does not just convert the answer. It switches to the products sold in each market where the fact base has them, such as metric concrete bags and UK plasterboard. Code values are quoted from the edition and country they belong to. US model codes and the UK Approved Documents are never treated as the same thing.

Where do the calculations come from?

From published sources, not from our own measurements. Formulas follow the method a building code, a standard or a manufacturer publishes. Every constant a calculator uses, such as a bag yield, a box coverage or a sheet size, is stored once in a fact file that records its publisher, document and the date it was checked. Each page builds its source list from the facts it actually uses.

We do not test, weigh or install products, and we do not give engineering advice. The full method, including how results are rounded, whose waste percentages are used and how code values are checked, is set out on how the calculators work. The editorial team page explains who maintains that fact base and what it checks.

How is the site paid for?

Through the Amazon Associates programme. Some calculator and guide pages list tools or materials that suit the job the page covers, with links to Amazon. If you buy through one of those links, the site can earn a commission. The price you pay is the same.

Commission does not decide which products appear, and it plays no part in any calculation. A calculator gives the same answer whether or not a page has product links. We show no prices, ratings or rankings. The details, including how those links are marked, are on how affiliate links work here.

There is no display advertising on the site at present. Pages load Google Tag Manager, which runs measurement tags such as Google Analytics to count visits and show which pages are used; the how we handle data page says what is collected, by whom and how to block it.

Is the content written by AI?

The page drafts are written with AI assistance, working from the fact base. No number on any page is typed in by the writer, whether a person or an AI. Each measurement, yield, percentage and code value is a reference to a sourced fact, filled in when the site is built. If a reference points to a fact that does not exist, the build stops and the page is not published.

Automated checks then look for banned marketing phrases, any claim to have tested something, ratings, prices, broken links and missing dates. Each calculator must also give the expected answer on its own worked check cases before it goes live.

What happens when something is wrong?

It is corrected at the source, and every page that uses it changes at once. Because each figure lives in one fact file, fixing it there updates every calculator and page that relies on it at the next build. The page's updated date changes too. If a calculator's answer changes, its check cases are updated so the old error cannot return.

We change a figure when a primary source supports the change: a newer code edition, a revised data sheet, or a closer reading of the original document. A different number on another website is not enough on its own. To send one, see report a formula error, which explains what to include.

What else is free to reuse?

Any calculator can be placed on another website with a short piece of code, and corrections reach embedded copies automatically. The add a calculator to your site page has the code. Diagrams you can reuse are on the free construction diagrams page, and our sourced data pages are collected in our data library. Each one states how to credit it.