Shoe size

The length of a person's foot is commonly defined as (a) the distance between two parallel lines that are perpendicular to the foot and (b) in contact with the most prominent toe and the most prominent part of the heel. Foot length is measured with the subject standing barefoot and the weight of the body equally distributed between both feet.

The sizes of the left and right feet are often slightly different. In this case, both feet are measured, and purchasers of mass-produced shoes are advised to purchase a shoe size based on the larger foot, as most retailers do not sell pairs of shoes in non-matching sizes.

Each size of shoe is considered suitable for a small interval of foot lengths, typically limited by half-point of the shoe size system.

A shoe-size system can refer to three characteristic lengths:

• The median length of feet for which a shoe is suitable. For customers, this measure has the advantage of being directly related to their body measures. It applies equally to any type, form, or material of shoe. However, this measure is less popular with manufacturers, because it requires them to test carefully for each new shoe model, for which range of foot sizes it is recommendable. It puts on the manufacturer the burden of ensuring that the shoe will fit a foot of a given length.
• The length of the inner cavity of the shoe. This measure has the advantage that it can be measured easily on the finished product. However, it will vary with manufacturing tolerances and only gives the customer very crude information about the range of foot sizes for which the shoe is suitable.
• The length of the "last", the foot-shaped template over which the shoe is manufactured. This measure is the easiest one for the manufacturer to use, because it identifies only the tool used to produce the shoe. It makes no promise about manufacturing tolerances or for what size of foot the shoe is actually suitable. It leaves all responsibility and risk of choosing the correct size with the customer. Further, the last can be measured in several different ways resulting in different measurements.[1]

All these measures differ substantially from one another for the same shoe. For example, the inner cavity of a shoe must typically be 15 mm longer than the foot, and the shoe last would be 2 size points larger than the foot, but this varies between different types of shoes and the shoe size system used. The typical range lies between ¹⁄₂ to ²⁄₃ inch (12.7 to 16.9 mm) for the UK/US size system and ⁴⁄₃ to ⁵⁄₃ cm (13.3 to 16.7 mm) for the European size system, but may extend to ¹⁄₄ to ³⁄₄ inch (6.4 to 19.1 mm) and ²⁄₃ to ⁶⁄₃ cm (6.7 to 20.0 mm).

Sizing systems also differ in the units of measurement they use. This also results in different increments between shoe sizes, because usually only "full" or "half" sizes are made.

The following length units are commonly used today to define shoe-size systems:

• The Paris point equates to ²⁄₃ centimetre (6.67 mm; 0.26 in). Whole sizes are incremented by 1 Paris point; this corresponds to 3.33 millimetres (0.131 in) between half sizes. This unit is commonly used in Continental Europe.
• The barleycorn is an old English unit that equates to ¹⁄₃ inch (8.47 mm). This is the basis for current UK and North American shoe sizes, with the largest shoe size taken as twelve inches (a size 12) i.e. 30.5 cm, and then counting backwards in barleycorn units, so a size 11 is 11.67 inches or 29.6 cm.
• Metric measurements in millimetres (mm) with intervals of 5 mm and 7.5 mm are used in the international Mondopoint system (USSR/Russia and Asia).

The sizing systems also place size 0 (or 1) at different locations:

• Size 0 as a foot's length of 0. The shoe size is directly proportional to the length of the foot in the chosen unit of measurement. Sizes of children's, men's, and women's shoes, as well as sizes of different types of shoes, can be compared directly. This is used with the Mondopoint and the Asian system.
• Size 0 as the length of the shoe's inner cavity of 0. The shoe size is then directly proportional to the inner length of the shoe. This is used with systems that also take the measurement from the shoe. While sizes of children's, men's and women's shoes can be compared directly, this is not necessarily true for different types of shoes that require a different amount of "wiggle room" in the toe box. This is used with the Continental European system.
• Size 0 (or 1) can just be simply a shoe of a given length. Typically this will be the shortest length deemed practical; but this can be different for children's, teenagers', men's, and women's shoes - making it impossible to compare sizes. For example, a women's shoe at size 8 is a different length from a men's shoe at size 8 in the US system, but not the British.

Some systems also include the width of a foot (or the girth of a shoe last), but do so in a variety of ways:

• Measured foot width in millimetres (mm) - this is done with the Mondopoint system.
• Measured width as a letter (or combination of letters), which is taken from a table (indexed to length and width/girth) or just assigned on an ad-hoc basis. Examples are (each starting with the narrowest width):
  • A, B, C, D, E, EE, EEE, EEEE, F, G (typical North American system, with the unlettered norm being D for men and B for women; also foot circumference in Japanese Mondopoint system).
  • 4A, 3A, 2A, A, B, C, D, E, 2E, 3E, 4E, 5E, 6E (variant North American)
  • C, D, E, F, G, H (common UK; "medium" is usually F, but varies by manufacturer—makers Edward Green and Crockett & Jones, among others, use E instead, but one maker's E is not necessarily the same size as another's).
  • N (narrow), M (medium) or R (regular), W (wide).

The width for which these sizes are suitable can vary significantly between manufacturers. The A–E width indicators used by most American, Canadian, and some British shoe manufacturers are typically based on the width of the foot, and common step sizes are ​³⁄₁₆ inch (4.8 mm).

Shoe size in the United Kingdom, Ireland, India, Pakistan and South Africa is based on the length of the last used to make the shoes, measured in barleycorns (​¹⁄₃ inch) starting from the smallest size deemed practical, which is called size zero. It is not formally standardised. Note that the last is typically longer than the foot heel to toe length by ​¹⁄₂ to ​²⁄₃ in or 1.5 to 2 barleycorns, so to determine the shoe size based on actual foot length one must add 2 barleycorns.

A child's size zero is equivalent to 4 inches (a hand = 12 barleycorns = 10.16 cm), and the sizes go up to size ​13 ¹⁄₂ (measuring ​25 ¹⁄₂ barleycorns, or 8 ¹⁄₂ inches (21.59 cm)). Thus, the calculation for a children's shoe size in the UK is:

child shoe size (barleycorns) = 3 × last length (in) − 12

equivalent to:

child shoe size (barleycorns) ≈ 3 × foot length (in) − 10.

An adult size one is then the next size up (26 barleycorns, or 8 ²⁄₃ in (22.01 cm)) and each size up continues the progression in barleycorns.[2] The calculation for an adult shoe size in the UK is thus:

adult shoe size (barleycorns) = 3 × last length (in) − 25

equivalent to:

adult shoe size (barleycorns) ≈ 3 × foot length (in) − 23.

Although this sizing standard is nominally for both men and women, some manufacturers use different numbering for women's UK sizing.

In Australia and New Zealand, the UK system is followed for men and children's footwear. Women's footwear follows the US sizings.

In Mexico, shoes are sized either according to the foot length they are intended to fit, in cm, or alternatively to another variation of the barleycorn system, with sizes calculated approximately as:

adult shoe size (barleycorns) = 3 × last length (in) − 25.5

equivalent to:

adult shoe size (barleycorns) ≈ 3 × foot length (in) − 23.5.

In the United States and Canada, there are different systems that are used concurrently. The size indications are usually similar but not exactly equivalent especially with athletic shoes at extreme sizes. The most common is the customary, described in more detail below, which for men's shoes is one size shorter than the UK equivalent, making a men's 13 in the US the same size as a men's 12 in the UK.

The traditional system is similar to British sizes but start counting at one rather than zero, so equivalent sizes are one greater.

The calculation for a male shoe size in the United States is:

male shoe size (barleycorns) = 3 × last length (in) − 24

equivalent to:

male shoe size (barleycorns) ≈ 3 × foot length (in) − 22.

In the "standard" or "FIA" (Footwear Industries of America) scale, women's sizes are men's sizes plus 1 (so a men's 10.5 is a women's 11.5):

female shoe size (barleycorns) = 3 × last length (in) − 23

equivalent to:

female shoe size (barleycorns) ≈ 3 × foot length (in) − 21.

There is also the "common" scale, where women's sizes are equal to men's sizes plus 1.5.

Children's sizes are equal to men's sizes plus ​12 ¹⁄₃. Children's sizes do not differ by gender even though adults' do:

child shoe size (barleycorns) = 3 × last length (in) − 11​²⁄₃

equivalent to:

child shoe size (barleycorns) ≈ 3 × foot length (in) − 16​¹⁄₃.

Children's shoe stores in the United States use a sizing scheme which ends at 13, after which the adult range starts at 1. Alternatively, a scale running from K4 to K13 and then 1 to 7 is in use.[3] K4 to K9 are toddler sizes, K10 to 3 are pre-school and 1 to 7 are grade school sizes.

Drawing of a Brannock Device (from US Patent 1,725,334)

A slightly different sizing method is based on the Brannock Device, a measuring instrument invented by Charles F. Brannock in 1925 and now found in many shoe stores. The formula used by the Brannock device assumes a foot length ²⁄₃ in (1.7 cm) less than the length of the last; thus, men's size 1 is equivalent to a foot's length of 7 ²⁄₃ in (19.47 cm):[4]

male shoe size (Brannock) = 3 × foot length (in) − 22.[5]

Women's sizes are one size up:

female shoe size (Brannock) = 3 × foot length (in) − 21.[5]

The device also measures the length of the arch, or the distance between the heel and the ball (metatarsal head) of the foot. For this measurement, the device has a shorter scale at the instep of the foot with an indicator that slides into position. If this scale indicates a larger size, it is taken in place of the foot's length to ensure proper fitting.[6]

For children's sizes, additional wiggle room is added to allow for growth.[6]

The device also measures the width of the foot and assigns it designations of AAA, AA, A, B, C, D, E, EE, or EEE. The widths are 3/16 inches apart and differ by shoe length.[4]

Some shoe stores and medical professionals use optical 3D surface scanners to precisely measure the length and width of both feet and recommend the appropriate shoe model and size.[7]

In the Continental European system, the shoe size is the length of the last, expressed in Paris points, for both sexes and for adults and children alike. Note that the last is typically longer than the foot heel to toe length by ​⁴⁄₃ to ​⁵⁄₃ cm or 2 to 2.5 Paris points, so to determine the shoe size based on actual foot length one must add 2 Paris points.

Because a Paris point is ​²⁄₃ of a centimetre, the formula is as follows:

shoe size (Paris points) = ​³⁄₂ × last length (cm)

equivalent to:

shoe size (Paris points) ≈ ​³⁄₂ × foot length (cm) + 2.

The European system is used in Austria, Belgium, Denmark, France, Germany,[8] Italy, Luxembourg, the Netherlands, Norway, Poland, Portugal, Spain,[9] Sweden, Switzerland, and most other continental European countries. It is also used in Middle Eastern countries (such as Iran), Brazil—which uses the same method but subtracts 2 from the final result, in effect measuring foot size instead of last size—and, commonly, Hong Kong. The system is sometimes described as Stich size (from Pariser Stich, the German name for the Paris point), or Stichmass size (from Stichmaß, a micrometer for internal measurements).

Measurement of foot length, width and perimeter (cirсumference) as defined in the Mondopoint standard

The Mondopoint shoe length system is widely used in sports industry to size athletic shoes, ski boots, skates, and pointe ballet shoes; it was also adopted as the primary shoe sizing system in the Soviet Union,[10] Russia,[11] East Germany, China,[12] Japan, Taiwan, and South Korea, and as an optional system in United Kingdom,[13] India,[14] Mexico, and European countries. The Mondopoint system is also used by NATO and other military services.

The Mondopoint system was introduced in the 1970s by International Standard ISO 2816:1973 "Fundamental characteristics of a system of shoe sizing to be known as Mondopoint" and ISO 3355:1975 "Shoe sizes – System of length grading (for use in the Mondopoint system)".[15] ISO 9407:2019, "Shoe sizes—Mondopoint system of sizing and marking",[16] is the current version of the standard.

The Mondopoint system is based on average foot length and foot width for which the shoe is suitable, measured in millimetres. The length of the foot is measured as horizontal distance between the perpendiculars in contact with the end of the most prominent toe and the most prominent part of the heel. The width of the foot is measured as horizontal distance between vertical lines in contact with the first and fifth metatarsophalangeal joints. The perimeter of the foot is the length of foot circumference, measured with a flexible tape at the same points as foot width. The origin of the grade is zero.

The labeling typically includes foot length, followed by an optional foot width: a shoe size of 280/110 indicates a foot length of 280 millimetres (11.0 in) and width of 110 millimetres (4.3 in). Other customary markings, such as EU, UK and US sizes, may also be used.

Because Mondopoint takes the foot width into account, it allows for better fitting than most other systems. A given shoe size shall fit every foot with indicated average measurements, and those differing by no more than a half-step of the corresponding interval grid. Standard foot lengths are defined with interval steps of 5 mm for casual footwear and steps of 7.5 mm for specialty (protective) footwear. The standard is maintained by ISO Technical Committee 137 "Footwear sizing designations and marking systems."

In Japan, Taiwan and South Korea, the Mondopoint system is used as defined by national standard JIS S 5037:1998 and its counterparts CNS 4800-S1093:2000 and KS M 6681:2007.

Foot length and girth (foot circumference) are taken into account.[17] The foot length is indicated in centimetres; an increment of 5 mm is used.

The length is followed by designators for girth (A, B, C, D, E, EE, EEE, EEEE, F, G), which are specified in an indexed table as foot circumference in millimetres for each given foot length; foot width is also included as supplemental information. There are different tables for men's, women's, and children's (less than 12 years of age) shoes. Not all designators are used for all genders and in all countries. For example, the largest girth for women in Taiwan is EEEE, whereas in Japan, it is F.

The foot length and width can also be indicated in millimetres, separated by a slash or a hyphen.

Historically the Soviet Union used the European (Paris point) system, but the Mondopoint metric system was introduced in the 1980s by GOST 24382-80 "Sizes of Sport Shoes" and GOST 11373-88 "Shoe Sizes", and lately by GOST R 58149-2018. Foot lengths are aligned to 5 mm and 7.5 mm intervals.

Standard metric foot sizes can be converted to the nearest Paris point (​²⁄₃ cm) sizes using approximate conversion tables; shoes can be marked with both foot length in millimetres, as for pointe ballet shoe sizes, or last length in European Paris point sizes (although such converted Stichmass sizes typically come ​¹⁄₂ to 1 size smaller than comparable European-made adult footwear, and up to ​1 ¹⁄₂ sizes smaller for children's footwear, according to ISO 19407 shoe size definitions). Optional foot width designations includes narrow, normal (medium or regular), and wide grades.

Infant sizes start at 16 (95 mm) and pre-school kids at 23 (140 mm); schoolchildren sizes span 32 (202.5 mm) to 40 (255 mm) for girls and 32 to 44 (285 mm) for boys. Adult sizes span 33 (210 mm) to 44 for women and 38 (245 mm) to 48 (310 mm) for men.

Differences between various shoe size tables, makers' tables or other tables found on the Web are usually due to the following factors:

• The systems are not fully standardised. Differences between shoes from different makers, which are due to different methods of measuring the shoes, different manufacturing processes, or different allowances[1] are sometimes related to different countries. A "German" size may then differ from a "French" size, although both countries use the Continental European system.
• Different widths may have the result that for wide feet, a shoe multiple sizes larger (and actually too long) may be required. This may also result in different size indications, especially if different : ) typical widths are attributed to different sizing systems or countries.
• Some tables for children take future growth into account. The shoe size is then larger than what would correspond to the actual length of the foot.[6]
• An indication in centimetres or inches can mean the length of the foot or the length of the shoe's inner cavity. This relation is not constant but varies due to different amounts of wiggle room required for different sizes of shoes.
• There are several US systems, which differ substantially for sizes far above or below medium sizes.

Further, some tables available on the Web simply contain errors. For example, the wiggle room or different zero point is not taken into account, or tables based on different US systems (traditional and athletic) are simply combined although they are incompatible.

Moreover, though the ISO had released a technical specification (ISO/TS 19407:2015) for converting shoe sizes across various local sizing systems, the organization noted that the problem of converting shoe sizes accurately has yet to be fully resolved. At best, its own published standards for shoe sizes conversions only serve as "a good compromise solution" for shoe-buyers.[18][19]

Please note that the following tables indicate theoretical sizes calculated from the standards and information given above.

• 
  Unofficial adult shoe sizes comparison
• 
  Unofficial children's shoe sizes comparison

The adult shoe sizes are calculated from typical last length, which is converted from foot length in mm by adding an allowance of two shoe sizes:

$${\displaystyle {\text{EUR shoe size}}={\frac {L+2\times {6.6{\bar {6}}}}{6.6{\bar {6}}}}={\frac {3}{20}}\times {L}+2}$$

$${\displaystyle {\text{UK shoe size}}={\frac {L+2\times {8.4{\bar {6}}}}{8.4{\bar {6}}}}-25={\frac {3}{25.4}}\times {L}-23}$$

where ${\displaystyle {L}}$ is foot length in mm.

Direct conversion between adult UK, European and Mondopoint shoe size systems is derived as follows:

$${\displaystyle L={\frac {20}{3}}\times \left({\text{EUR shoe size}}-2\right)={\frac {25.4}{3}}\times \left({\text{UK shoe size}}+23\right)}$$

$${\displaystyle {\text{EUR shoe size}}={1.27\times \left({\text{UK shoe size}}+23\right)}+2}$$

$${\displaystyle {\text{UK shoe size}}={\frac {{\text{EUR shoe size}}-2}{1.27}}-23}$$

Exact foot lengths may contain repeating decimals because the formulas include division by 3; in practice, approximate interval steps of 6.67 mm and 8.47 mm are used, then resulting lengths are rounded up to 0.1 mm, and shoe sizes are rounded to either 0.5 size points or closest matching Mondopoint size.

Children sizes are approximations converted from foot length by adding an 8% allowance at the toes and matching the result to the closest practically available last size.

The standard also includes quick conversion tables for adult shoe sizes; they provide matching sizes for shoes marked in Mondopoint, European, and UK systems. Converted values are rounded to a larger shoe size to increase comfort.