Tile calculator

Common questions

How many tiles come in a box?

It depends on the size and the maker: 600 × 600 mm tiles often come 4 to a box, 300 × 600 mm 6 to 8, and 300 × 300 mm 10 or more. The number is printed on the box: enter it and the calculator rounds the boxes up and shows the spare tiles.

Is a “2 × 2 ft” tile really 24 × 24 inches?

Usually not: most tiles sold as 2 × 2 ft are 600 × 600 mm, which is 23.6 in. Over a big floor that is about 3% more tiles than a true 24 × 24 in count, so pick the metric size when the box says mm.

How much waste should I allow?

7% for straight laying in square rooms, 10% for rooms with many corners or pillars, and 12–15% for diagonal patterns or large tiles that need cutting. Buy the whole quantity from one batch — a later batch can be a different shade.

Why does a window above the tiles not reduce the wall tiles?

Only the part of a door or window that sits below the tiled height removes tiles. A bathroom ventilator at 6 ft takes nothing off tiles that stop at 5 ft; a door from the floor to 7 ft takes off its width × the tiled height.

What goes under the tiles?

A 1 in bed of 1 : 4 cement–sand mortar with cement slurry on the back of each tile for floors; tile adhesive on a rough plaster coat for walls and for porcelain. Use the adhesive coverage printed on the bag. Bathroom floors need waterproofing and a 24-hour water test before the bed goes down — see the guide.