How to Calculate How Many Tiles You Need
Tile maths trips people up because tiles are sold by size in centimetres while floors are measured in square metres. Here is how to bridge the two.
What is the Tiles Needed Calculator?
The calculator converts your tile size from centimetres to square metres, divides the floor area by the area of one tile, then adds your waste percentage for cuts around edges and the odd breakage. The final figure is rounded up, since you cannot buy part of a tile.
How to use it
- Enter the floor area in square metres.
- Enter the tile length and width in centimetres.
- Enter a waste percentage and press Calculate.
Worked example
Floor 20 square metres, tiles 30 by 30 cm, waste 10 percent: the tool gives 245 tiles.
How many 30 cm by 30 cm tiles cover 20 square metres with 10 percent waste?
You need 245 tiles. Each tile covers 0.09 square metres, so 20 square metres needs about 222.22 tiles before waste, and adding 10 percent brings it to 244.44, which rounds up to 245 tiles to buy.
Frequently asked questions
What waste percentage should I use?
10 percent is a common allowance for a straightforward room. Use 15 percent or more for diagonal layouts or rooms with many corners and cuts.
Are the tiles assumed to be square?
No. You enter length and width separately, so rectangular tiles work just as well.