Normally our boots run neither small nor large, if they do, it will say so in the product description. If you are between sizes, we recommend to choose the larger size. When trying on the boots, remember, that they are made of real leather. By wearing them, they will get wider.
All Fernando Berlin shoe sizes are USW (FIA).
This shoe size chart will give you an overview. If you have more doubts, we recommend this article in Wikipedia, which includes a more excact size chart.