Tile Calculator

How many tiles and boxes a surface needs.

Lumber is sold in nominal dimensions that no longer match its actual size, and concrete is ordered in whole bags or cubic yards, so quantities round up. Local building codes set minimum standards for stairs, headroom and slab thickness.

American construction estimates are drawn in feet and inches, and materials are sold with a waste allowance built in — around 5-10% for tile and flooring, more where cuts run on the diagonal. Concrete bags are labelled by yield in cubic feet, while soil, mulch and gravel are bought by the cubic yard.

Tile quantities depend on the area covered, the tile size and the pattern, since a diagonal layout wastes more at the edges than a straight one. An allowance of about ten percent covers cuts and breakage, and spare tiles matter because dye lots vary.

Ordering to the worked area with no allowance is the commonest way a job runs short: the estimate here is net of offcuts and breakage.

Estimating is a sequence of conversions — dimensions in feet and inches, depth in inches, coverage per bag or per roll — and every step carries its own rounding. Building departments publish the minimum standards that decide whether a stair, a rail or a slab is compliant.

Tile Calculator sits with the rest of the library's everyday work, and it rests on the same material-estimating arithmetic the way a manufacturer's label or a timetable does. Its answer is only as good as the assumptions standing behind it.

The quantities it works from — area to tile, tile length, tile width and waste allowance — are the ones a real material-estimating question actually turns on, and each carries a convention of its own, set out below.

Everyday arithmetic in the United States carries conventions that are easy to miss: dates run month before day, distances and weights follow customary units, and prices are quoted before tax. Those conventions make a surprising share of daily sums come out differently from the same question asked elsewhere.

The figures in this section follow American practice unless the subject itself is international.