Choosing your size.
If you are unfamiliar with European sizing, it can be useful to measure your feet before ordering. Doing so will take just a few minutes, and save you the unnecessary time involved in exchanging your shoes. You can estimate your shoe size by measuring your foot length toe to heel.
Place your heel against the wall and on a piece of paper mark the tip of your longest toe. Measure the distance between the wall and your toe marking. Repeat the process for your other foot. Use the measurement of your larger foot as your shoe size.