About CalcGallery

What this is

CalcGallery works out how much material a job needs. Not the raw geometry, which any calculator can do, but the number you can act on: how many bags, how many boxes, how many sheets, with the waste allowance included and the quantity rounded to something you can actually buy.

How the calculators are built

Every calculator publishes its formula on the page, with your own numbers substituted into it, so you can check the working rather than trust it. Every physical constant, including coverage rates, densities and premix yields, is listed with a source and is editable, because the figure printed on the product in front of you beats any published average.

Every waste allowance is a named situation rather than a hidden percentage. A diagonal tile layout wastes more than a straight lay, and the calculator says so and shows you the number before waste alongside the number to buy, so the gap reads as a margin rather than a mistake.

What it will not do

These are estimates for planning. They are not engineering, they are not code compliance, and they do not know your ground conditions. Where building codes matter, the pages say to check yours, because the rules genuinely differ by jurisdiction and a confident wrong answer is worse than no answer.

Telling us when we are wrong

Every calculator page has a link to report a problem. Accuracy complaints are the most useful messages we get, and a calculator found to be wrong gets fixed or removed.