The top 10 important questions about shoe sizes:

• 01.

  Why are there so many different shoe sizing systems in the world?

  The shoemaker's craft has existed for many hundreds of years. It has developed differently all over the world. In the Anglo-Saxon world (i.e. mainly in Great Britain and North America), shoe sizes are based on inches. In the rest of the world, centimetres and millimetres form the basis for defining shoe sizes. While, on the one hand, the length of a barley grain was defined as a shoe size. In European shoe sizes, it is the seam spacing of old sewing machines (i.e. the Paris stitch), which defines the length of a shoe size.

  While some shoemakers use the foot length as a reference for shoe size, others use the interior length of the shoe as a reference for shoe size. Some cobblers have chosen the foot length as the zero point (i.e., the start of shoe size numbering). For example, Shoe Size 0 starts at a foot length of 0. Others (e.g., in the UK and the USA) have assumed a minimum foot length and started numbering shoe sizes from there.

  Based on the uniform national and international standards of shoe size, many manufacturers, especially sports shoes companies such as adidas, Nike, Puma and Vans, publish their own shoe size tables.

• 02.

  Why do shoe sizes vary so much?

  Due to a lack of standards, the shoe sizes of one sizing system (EU shoe sizes, UK shoe sizes, US shoe sizes or Mondopoint shoe sizes) look different. Since the systems for shoe sizes are only partially standardised, these differences result solely from different measuring methods, manufacturing processes and tolerances.

  Furthermore, different foot widths often mean that, for example, shoes with extra large shoe size are required if the foot is wide. Tables for shoe sizes sometimes include more or less toe room when assigning the shoe size. The growth of children's feet is priced according to shoe sizes in varying degrees. Many shoe size tables are also simply wrong—even with the same manufacturer—the shoe sizes sometimes contradict each other.

• 03.

  Is there an international standard for shoe sizes now?

  Yes, almost. With “ISO/TS 19407:2015”, the ISO (International Organization for Standardization) has developed a technical specification for the conversion of shoe size systems, which is also used by our Shoe Size Converter. The ISO's planned approach is to make this pre-standard the global standard for the allocation and conversion of shoe sizes over the next few years. This should finally guarantee consumers a reliable and uniform calculation of shoe sizes.

  However, the different size systems are to remain in place. From this point of view, the IS0 also points out that, due to the conversion from inches to centimetres (1 inch corresponds to 2.54 centimetres), it will always be necessary to round up or down when converting to the respective shoe size of the other system. Despite the fixed conversion formulas of the ISO, shoe sizes will continue to be converted approximately into each other. However, this ISO pre-standard, with its fixed methodology, offers the best compromise to provide manufacturers and consumers with reliable conversions of shoe sizes.

  The reference size used by the ISO is always the foot length in cm or mm.

Convert Shoe Sizes

• 04.

  What is the Mondopoint system?

  The Mondo­point shoe­size­system is the only one that was defined in accordance to ISO standard (ISO 9407) in 1991. This distinguishes the MP system from the other three major shoe size systems (EU, UK, US), which, as described above, are not yet subject to an international standard but to a so-called pre-standard. While in these systems, the reference size for a shoe size is sometimes the foot length, or sometimes the interior length. In the Mondopoint shoe size system, the foot length in centimetres or millimetres is strictly used as the reference size for calculating the shoe size. Mondopoint shoe sizes simply correspond to the foot length in millimetres, whereby a subdivision of the shoe sizes in 5-mm steps has become established.

  Especially in Russia, China, Japan and Southeast Asia, the indication of shoe sizes in centimetres or millimetres is well established. This simple system for shoe sizes has also become established for military shoes, safety shoes or ski shoes.

• 05.

  What is a European (EU) shoe size of a UK or US shoe size and vice versa?

  European shoe size is applicable, for example, in Germany, France, Italy, Portugal and Spain and everywhere in Europe except the UK. Hence, this continental European shoe size system defines the EU shoe sizes. An EU shoe size is two-thirds of a centimetre (0.667 cm) in length, which originally correspond to the length of a Paris stitch (i.e., the seam distance of sewing machines used at the time for sowing on the sole. With the conversion to UK shoe sizes or US shoe sizes, it should be noted that these calculate with different units of length. This is because they use one-third of an inch (0.847 cm) as the unit of measurement for a shoe size. This shoe size is also historically traced back to the length of a barleycorn.

  In addition, EU shoe sizes start at a foot or inner shoe length of 0, whereas UK and US shoe sizes start numbering shoe sizes at other lengths. These also differentiate between shoe sizes for children or babies and adults. For US shoe sizes, there is also a distinction between men's and women's shoe sizes, and thus it is complicated. It is best to use our Shoe Size Conversion Calculator to help you calculate your EU shoe size into UK or US shoe sizes and vice versa. Among many other things, the conversion formulas for all shoe sizes are explained and derived there.

• 06.

  Why are US women's sizes bigger than men's sizes?

  Unlike EU shoe sizes, both UK shoe sizes and US shoe sizes do not start numbering shoe sizes until a certain foot or inner shoe length is reached. In the UK, the first 12 inches of a shoe are not assigned a shoe size. The following every third of an inch (0.847 cm) is assigned Shoe Sizes 13 as children's shoe sizes. The shoe sizes for adults start after the children's shoe sizes with Shoe Size 1. In the USA (i.e., in the US shoe size system), the numbering starts at slightly less than 12 inches. As a result, it has become internationally accepted that US shoe sizes are always one size larger than UK shoe sizes for the same length.

  Another difference between the US system and the UK system is that, in the numbering for adults, abiding by the Children’s Size 13 helps to distinguish between a man and woman. The numbering of the shoe sizes for men starts (as in the UK system) at Shoe Size 1. The numbering of the women's shoe sizes for US sizes starts in the same place with Shoe Size 0. Therefore, UK Shoe Size 8 sometimes corresponds to US Shoe Size 9 for men and US Shoe Size 10 for women.

• 07.

  Are children's shoes measured differently?

  The rapid growth of the feet and the width of the foot should be taken into account. In the official ISO specification, for example, toe clearance is given special consideration when calculating children's shoe sizes. While shoe sizes for adults, regardless of the actual foot length, always include two shoe sizes as space for toe clearance. For children, the exact foot length is taken into account for the shoe size. According to ISO, 8 percent of the foot length is included as a surcharge in the formula for the children's shoe size.

• 08.

  Do the shoe sizes of sports shoes turn out differently?

  It is no doubt that sports shoes are smaller than other shoes. So, for the same length, they have a higher shoe size. If you normally wear a US Shoe Size 9, it is preferable to choose a Shoe Size 10 or higher from many well-known sporting goods manufacturers for the shoe to fit. Naturally, feet are particularly emphasized in sport shoes, which is why it is highly recommended to try them on before buying, especially when choosing a different brand.

• 09.

  Do feet change size during the day?

  Yes, feet expand during the day. You should keep this in mind when trying on new shoes and choosing the right shoe size. Therefore, the perfect time to try on shoes should start in the afternoon.

• 10.

  What are the cut sizes for men's and women's shoes?

  According to Statista surveys, the average shoe­size for women is split evenly between Shoe Size 38 and Shoe Size 39. For men, the most common shoe size at 19 percent is Shoe Size 42. For both men and women, the average foot size has hardly changed in recent decades despite increasing body size. On the other hand, a slight tendency towards wider feet can be observed for both. If this trend continues, shoe manufacturers will have to increasingly offer different shoe sizes in the future by taking into account the width of the foot.