Free calculators that get the numbers right.

Each calculator uses standard industry formulas, and every one of them prints the formula it used on the same page so you can check the arithmetic yourself. They are estimates for planning: confirm against your project specs, your supplier's actual coverage rates and your local building code before ordering.

Usually coverage rates, bag yields or order minimums. Products of the same nominal size can cover different areas, and many suppliers round up to a full pallet, roll or truckload. Enter the figure printed on the product you are actually buying rather than the default, and the two numbers should converge.

It depends on the material and how complicated the job is, so each calculator suggests a default and explains it on the page. As a rule, simple rectangular work needs less than a layout full of cuts, angles and openings — and the offcuts you cannot use are what you are budgeting for.

Yes. Every calculator has a unit toggle, and switching the site's language switches the default measurement system with it. You can change it back at any point without losing what you have already typed in.

No account, and nothing is uploaded. Saved calculations, favourites and projects are stored only in your own browser, which also means they do not follow you to another device and clearing your browser data removes them.