How tile calculator works
This calculator tells you how many tiles to buy for a floor or wall. Enter the area to cover, the length and width of one tile, and a waste percentage to allow for cuts, breakages and pattern matching.
It converts the tile dimensions into the same area unit as your surface (square feet or square meters), divides the surface area by one tile's area to get the base tile count, then adds the waste factor and rounds up to a whole tile. If you enter tiles per box, it also rounds up to whole boxes and reports the leftover tiles.
A 10% waste allowance is standard for a straight-lay grid pattern; diagonal or herringbone layouts and large-format tiles need 15-20% because cuts waste more. Natural stone and patterned tiles may need even more so you can match veining or repeats across the room.