The first thing to do is measure your space. You can either do this yourself with a tape measure or if you're not confident or have a trickier area to tile, ask your tiler to do the measuring for you. Some tilers will give you a measurement in square metres, but what you really need is the dimensions by length and width, in centimetres.
Top tip – don’t forget to factor in doors, windows and any obstacles that won’t need to be tiled!