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.
Frequently asked questions
How do I calculate how many tiles I need?
Divide the area to cover by the area of one tile. Add a waste allowance (10% is standard) for cuts and breakage, then round up. This calculator does all of that and, if you give it tiles per box, rounds up to whole boxes too.
What waste percentage should I use?
10% for a simple straight-lay grid on a rectangular room. Use 15% for diagonal or patterned layouts, and 15-20% for large-format tiles or rooms with lots of odd corners. Buy extra if the tile is being discontinued, so future repairs match.
Can I enter the tile size in centimeters and the area in square feet?
Yes. The calculator converts the tile dimensions into the same unit as your area automatically. Choose the area unit (sq ft or sq m) and the tile unit (inches or cm) independently and the math stays consistent.
Why does it round up to whole boxes?
Tiles are sold in whole boxes, not loose. Rounding up to the next box guarantees you have enough and a few spares for future repairs. The extra-tiles count tells you exactly how many surplus tiles that rounding produces.
