Free tile calculator. Tile count with 10–15% cut-and-waste allowance for floors, walls, and splashbacks.
This calculator counts tiles, adhesive and grout for a floor or wall, at the tile size and joint width you are using. Two of the numbers on this page used to be wrong in instructive ways, and both are fixed.
A tile occupies its own size plus the joint beside it, so the area one tile covers is its width plus the gap, times its height plus the gap. Tile count is the area divided by that, rounded up.
Wastage is 10%, or 15% if you switch on the diagonal or complex layout option, because a diagonal set-out cuts every perimeter tile.
A joint width of zero now stays zero. It used to be silently turned into 3mm, so a butt-jointed floor was sized at 303 by 303mm tiles while the page told you it was working at a 3mm joint — and under-ordered accordingly.
Sizes offered are 300 by 300, 400 by 400, 600 by 600 and 300 by 600mm, plus a custom size.
The page used to print roughly 0.5 kilograms per square metre under a sub-label saying it was based on your joint width. It was a constant. It ignored both the joint width and the tile size, so the label was claiming a derivation the number did not have.
That matters because the real figure moves a long way. A 10mm joint on 300 by 300 tiles takes over three times the grout of a 3mm one, and the page reported the same 0.5 for both.
Grout is now worked out from the geometry of the joints themselves — the length of joint around a tile of a given size, at your joint width and your tile thickness. That is why the tile thickness field is there: a deeper tile means a deeper joint, and more grout sitting in it.
Adhesive is counted at 4 kilograms per square metre.
Waterproofing, substrate preparation and movement joints are specification decisions. Check them against your plans and the tile and adhesive manufacturers' systems, and confirm coverage figures on the product, before you order.