Getting the wrong shoe size can mean disappointments, lost time, and even loss of money if the retailer doesn't accept returns. This web site contains shoe size conversion charts for consumers who are looking to buy footwear outside of their country.
There are several things to keep in mind when using a shoe size conversion chart. Firstly, sizes used in the United States are not the same used in European countries such as the United Kingdom and Spain. Secondly, when buying different brands of shoes, your shoe size may not automatically convert. For example a size 11 Steve Madden™ shoe may be a size 10 ½ Nike™ shoe.
There is no across the board standard that will apply to every country and brand. Shoe manufacturers usually base their shoe sizes around one of two sizing methods. The first is the using the "last" length. The last is a foot-shaped template on which the actual shoe is created. Other manufacturers will use the inner-cavity of the shoe as a means for determing a shoe size. The inner-cavity is the area inside the shoe where the actual foot resides.