If you are unsure on how many tiles you will require in order to cover a certain area and which size of tile you will need, then use our free online Tile Calculator to find out how many tiles you will need. In order to make sure you take account for damaged tiles or tiles that need to be cut, it's a good idea to add on 10% from what your final calculation equals.
Again, in order to account for any cutting and wasted or damaged tiles, add an extra 10% to your final result. While cutting tiles and shaping them you may cut them wrong or they make break, which is why it's important to add that 10%. If you get close to the end of a project and you notice that you are lacking only a few tiles, you'll feel a sinking feeling inside. By extra tiles than you expect to use and you'll avoid situations like that.