Work out how many tiles and boxes a floor or wall needs from its size, the tile size, the grout gap and the waste.
The number of tiles is the area plus the extra for waste, divided by the space one tile takes including its grout joint, rounded up to a whole tile. The default example is a 4 m by 3 m floor, which is 12 m², with 60 cm tiles and a 3 mm grout gap. One tile and one joint take 0.603 m × 0.603 m = 0.3636 m². With 10% extra the floor needs 12 × 1.1 = 13.2 m², and 13.2 ÷ 0.3636 = 36.30, so 37 tiles. In feet and inches, 12 ft by 10 ft with 12 in tiles and a 0.125 in joint is 120 sq ft; with 10% extra it needs 132 sq ft, and each tile takes 1.0209 sq ft, so 129.29 rounds up to 130 tiles. The box under the answer shows every step. You can type the length and width or, if you already know it, the total area, and the page never subtracts doors, baths or cut-outs, so take those off first.
Tiles are cut at the edges, and some break, so you order more than the bare area. The page starts with 10% for a straight lay and 15% for a diagonal lay, because angled cuts waste more. One flooring guide puts a simple straight layout at 5% to 7%, medium tiles at 7% to 10%, and diagonal at 15% to 25%, which shows the range is wide. Pick Custom and type your own percentage, from 0 to 100, if the room has many corners, small mosaic tiles or a pattern. For the example floor, 15% gives 12 × 1.15 ÷ 0.3636 = 37.95, which is 38 tiles. One grout joint is added to each tile's length and to its width (60 cm plus 3 mm is 60.3 cm), so a wider joint means fewer tiles: set it to 0 for tiles laid tight. In inches type the gap as a decimal, such as 0.125 for 1/8 in.
Tiles are sold in boxes, so type the tiles per box from the label and the page rounds the tile count up to whole boxes and shows the tiles left over. With 10 per box the 37 tiles of the metric example are 4 boxes, which is 40 tiles with 3 left over. A price is optional, per tile or per box. At 2.50 a tile the 37 tiles cost 92.50, and at 30.00 a box the 4 boxes cost 120.00. The amounts have no currency symbol, and the cost is only the tiles, not grout, adhesive, trim or delivery. Pricing by the box needs a box size, and the page asks for it.
It assumes tiles are laid in a grid, with every tile the same size and a single area. The count is the area with your extra percentage, but never fewer than a grid of whole tiles that covers the length and width (a 1 m by 1 m floor of 60 cm tiles needs 4, even with 0% extra); in total-area mode there is no grid check. It does not know about patterns with several tile sizes, borders, a pattern that must match, or tiles that must be cut in a particular direction. Natural stone and handmade tile vary in size and shade, and tile from different batches can differ, so buy everything for one area together and keep a spare box. The result is an estimate worked out from the numbers you type, and the coverage printed on the box has the last word.
37 tiles. The floor is 12 m², and with 10% extra it needs 13.2 m². With a 3 mm joint each tile takes 0.603 × 0.603 = 0.3636 m², so 13.2 ÷ 0.3636 = 36.30, rounded up to 37. With 15% extra for a diagonal lay it is 38.
130 tiles. The room is 120 sq ft, and with 10% extra it needs 132 sq ft. A 12 in tile with a 1/8 in joint takes 1.0209 sq ft, so 132 ÷ 1.0209 = 129.29, rounded up to 130. That is 13 boxes of 10.
The page uses 10% for a straight lay and 15% for a diagonal lay, and you can type your own. A flooring guide gives 5% to 10% for straight layouts and 15% to 25% for diagonal, so complex rooms or small tiles may need more.
Yes, if you want an exact count. Each tile takes its own size plus one joint, so a 60 cm tile with a 3 mm joint takes 60.3 cm. With 60 cm tiles a 3 mm joint changes the count from 12 × 1.1 ÷ 0.36 = 36.67 to 36.30, which still rounds to 37 tiles.
Divide the tile count by the tiles per box and round up. For 37 tiles and 10 per box that is 3.7, so 4 boxes, with 3 tiles left over. Type the tiles per box from the label.
No. The calculation runs in your browser and the sizes stay in this tab. They are not uploaded or stored on your device. Reloading the page puts the example back. The page only counts that a result was shown, without any of your numbers.