Tile Calculator
Estimate the total number of tiles required for room flooring or wall tiling.
Recommended: 10% for grid layout, 15% for diagonal layout.
Tile Estimation Results
Room Area: 100 sq ft
Total Coverage with Waste: 110 sq ft
Buy more than the area says
Start with the room area divided by the tile area, and treat that as a floor rather than an answer. Tiles must be cut at walls and around fixtures, and offcuts are rarely reusable, soevery real job needs a waste allowance — commonly 10% for a straight layout, and 15-20% for diagonal or herringbone patterns, which generate far more part-tiles.
Buy the overage in the same purchase. Tiles are manufactured in batches, and colour varies measurably between them; a replacement box bought months later frequently will not match, which is why the batch or lot number is printed on the box. Keeping a few spares after the job is finished also matters, since a cracked tile in five years is otherwise impossible to replace invisibly.
Two things the area calculation omits. Grout lines add to the covered area, which slightly reduces the tile count on small formats and is usually absorbed into the waste allowance. And irregular rooms should be broken into rectangles and summed rather than approximated — a bay or an alcove measured roughly can throw the count out by a full box.
Frequently asked questions
How much extra tile should I buy?
For most projects, add 10% waste for cuts and breakage. For diagonal patterns or complex areas, add 15–20% extra.
What tile sizes can I calculate for?
You can enter any custom tile size in inches. Common sizes include 12×12, 18×18, 24×24, and 12×24 inches.
Does the calculator include grout lines?
The calculator works from nominal tile dimensions. The waste percentage covers grout gaps and cut tiles at edges.
How do I calculate tiles for a diagonal or patterned layout?
Diagonal layouts generate far more cuts at the perimeter, so add 15-20% waste rather than the usual 10%. Patterned tile that must align across joints needs more again, since offcuts often cannot be reused. Herringbone and chevron layouts are the most wasteful of all.