Tiles are counted from the area and the size of one tile, then rounded to whole boxes. Adhesive and grout follow from the same area.
Tiles per square metre
One tile covers its length times its width. A 600 × 600 mm tile is 0.36 m², which is 2.78 a square metre. A 300 × 300 mm tile is 0.09 m², which is 11.1 a square metre.
| Tile | Area each | Per m² |
|---|---|---|
| 300 × 300 mm | 0.090 m² | 11.11 |
| 600 × 300 mm | 0.180 m² | 5.56 |
| 600 × 600 mm | 0.360 m² | 2.78 |
A worked floor
A 10 m² floor in 600 × 600 mm tiles is 27.8 tiles net. With 10% for cuts it is 30.6, so 31 tiles. At 4 tiles a box, that is 8 boxes, 32 tiles.
The same floor in 300 × 300 mm tiles is 123 tiles. Check how many are in a box; it is printed on the pack and varies by range.
Waste
Ten per cent suits a straight lay. A diagonal lay cuts every edge tile, so the calculator offers 15%. Large tiles in a small room waste more than the percentage suggests, because each cut leaves a big offcut.
Adhesive and grout
Adhesive starts at 4 kg a square metre and a 20 kg bag, the size Bunnings lists for Dunlop tile adhesive. 10 m² is 40 kg, two bags. The rate depends on the trowel and the tile, so read the bag.
Grout depends on the joint. With 3 mm joints, 6 mm deep, 600 × 600 mm tiles need about 0.1 kg a square metre. Smaller tiles have more joint per square metre and take more. The grout bag's own coverage table is better than this estimate.
Figures are estimates for a shopping list. Check the pack or datasheet before you buy.