US shoe sizes - American shoe sizes and their conversion

Updated on by Stefan Banse

The US shoe size converter converts any US shoe size into the other most important shoe size systems like UK or EU shoe sizes. Likewise, European EU sizes and British UK sizes are converted into the appropriate US shoe sizes. Of course, US shoe sizes are calculated for both women and men. Also US sizes are calculated for children and babies.


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Calculate US Shoe Sizes - An Example

Information on American shoe sizes, i.e. US sizes

The US shoe size system, like the British, is based on the inch (2.54 cm) unit of length. Also in North­America, each shoe­size is equal to one third of an inch, i.e. 0.847 cm. Unlike in Great Britain, shoe size 0 starts at 9.95 cm. This means that the first 3 and eleven twelfths of an inch are not used for size numbering in the US sizing system. From a foot length of this 9.95 cm, 13 children's shoe sizes of 0.847 cm each are initially defined, after which the sizes for women start again with shoe size 0 and for men with size 1. In practice, the US system is largely aligned with the UK system. However, with the exception that for the same foot length, US men's sizes are around one size larger and US women's sizes are around two sizes larger than the corresponding UK shoe sizes. The reference size for US sizes is usually, as in the ISO standard used here, the foot length, but sometimes also the inside length or the length of the last of the shoe. This is one of the reasons why shoe sizes vary so much.

Calculation of US shoe sizes according to ISO/TS 19407:2015

The US shoe size calculator determines sizes according to ISO. The US shoe size tables presented here were also created according to this ISO specification. The ISO (International Organization for Standardization) has defined the international conversion of shoe size systems and thus issued an international pre-standard. Nevertheless, there are very often deviations from the American shoe sizes theoretically calculated here. Shoes are therefore often smaller or larger than assumed on the basis of the size, depending on the manufacturer or simply because of deviating standardisation.

ISO formula for calculating the US shoe size for men

US shoe size men
=
(foot length + 2 × 0,847) / 0,847 − 24

The formula for US men's sizing makes it clear that each size equals 0.847 cm. For toe room, two sizes are added, i.e. 2 × 0.847 cm. Finally, 24 sizes are subtracted in the formula. These are the "empty", slightly less than 12 sizes at the beginning and the following 13 children's sizes. However, exactly 24 US sizes are subtracted because the US system, as described above, is aligned with the UK system with the exception that one size more is allocated for the same foot length.

ISO formula for calculating the US shoe size for women

US shoe size women
=
(foot length + 2 × 0.847) / 0.847 − 23

The formula for US women's sizing again shows that each size equals 0.847 cm. For toe room, two sizes are also added here, i.e. 2 × 0.847 cm. At the end, in contrast to the men's sizes, 23 sizes are subtracted from the formula instead of 24. This is because the numbering of the US sizes for women starts with zero after the 13 children's sizes, whereas for men it starts with one. However, exactly 23 US sizes are subtracted because, as described above, the US system is aligned with the UK system with the exception that for the same foot length, US women's sizes are about two sizes larger than the corresponding UK shoe sizes.

ISO calculation formula for US shoe size for children

US children's size
=
foot length × 1.08 / 0.847 − 11.5 + 0.4

Compared to the adult formula, a surcharge of eight percent of the foot length is added for toe clearance instead of the two English sizes. Here, however, only 11.5 instead of 12 "empty" sizes are deducted at the beginning compared to the UK children's size, so that the US children's sizes are ultimately always 0.5 sizes above the UK children's sizes. Finally, for the ISO formula, 0.4 sizes are added again to obtain practical size tables.

US Shoe Size Chart for US Sizes for Women and Men

According to the official ISO technical specification, the following shoe size table results for all American shoe sizes. Unlike the other shoe size­systems, US shoe sizes make a distinction between US women's shoe sizes and US men's shoe sizes.

US adult shoe size chart according to ISO specification ISO/TS 19407:2015
US women US men UK Mondo­point EU
4 3 2 210 34
4.5 3.5 2.5 215 34.5
5 4 3 220 35
5.5 4.5 3.5 225 35.5
6 5 4 230 36.5
6.5 5.5 4.5 235 37
7 6 5 235 37.5
7.5 6.5 5.5 240 38
8 7 6 245 39
8.5 7.5 6.5 250 39.5
9 8 7 255 40
9.5 8.5 7.5 260 40.5
10 9 8 260 41.5
10.5 9.5 8.5 265 41.5
11 10 9 270 42.5
11.5 10.5 9.5 275 43.5
12 11 10 280 44
12.5 11.5 10.5 285 44.5
13 12 11 290 45.5
13.5 12.5 11.5 290 46
14 13 12 295 46.5
14.5 13.5 12.5 300 47
15 14 13 305 47.5
15.5 14.5 13.5 310 48.5
16 15 14 315 49
16.5 15.5 14.5 320 49.5
17 16 15 320 50
US women US men UK Mondo­point EU

US size chart for adults to print

Here you will find the "US shoe size chart for adults" as an image to print out. For on the road and in the shoe shop. Always at hand. >>
US Shoe Size Chart for Adults

US Shoe Size Chart for US Sizes for Children

In the USA and the UK, children­shoe­sizes are assigned different numbers than adults for shoe­sizes. After a total of 13 US children­s shoe­sizes, the US adult shoe­sizes follow, starting with shoe size 0 for women and size 1 for men. Based on the ISO specification, the following shoe size chart applies to all US children's shoe sizes.

US shoe size chart for children according to ISO specification ISO/TS 19407:2015
US Foot length, inch Foot length, cm Mondo­point EU UK
44.712.012019.53.5
4.54.812.3125204
55.012.720.54.5
5.55.113.0130215
65.213.321.55.5
5.313.513522
6.55.413.814022.56
75.614.2236.5
7.55.714.614523.57
5.814.824
85.915.015024.57.5
8.56.115.4155258
96.215.725.58.5
9.56.316.0160269
6.416.426.5
106.516.6165279.5
10.56.716.917027.510
116.817.32810.5
11.56.917.617528.511
127.017.91802911.5
7.218.229.5
12.57.318.51853012
137.418.830.512.5
13.57.619.21903113
17.719.519531.513.5
7.819.832
1.57.920.020032.51
28.020.4205331.5
8.120.733.5
2.58.321.0210342
38.421.334.52.5
3.58.521.7215353
48.722.022035.53.5
8.822.436
4.58.922.622536.54
59.123.0230374.5
9.123.237.5
9.323.6235385
US Foot length, inch Foot length, cm Mondo­point EU UK

In this size chart for US shoes according to ISO, some fields are not filled. This is because the official ISO formula has not determined a corresponding size in the other size unit at the corresponding position. However, the US shoe size converter also determines the corresponding rounded sizes for the missing fields. The calculation and rounding are explained in the results window behind the info buttons.

US size chart for children to print

Here you will find the "US shoe size chart for children" as an image to print out. For on the road and in the shoe shop. Always at hand. >>
US Shoe Size Chart for Children

What are EU sizes 38 or 43 in UK or US sizes?

If you want to know which shoe sizes correspond to e.g. EU shoe size 38, 42 or 43, you can either use the shoe size converter, use the matching shoe size chart or look up your US or UK shoe size on the following pages.

What is EU shoe size 20?, What is EU shoe size 21?, What is EU shoe size 22?, What is EU shoe size 23?, What is EU shoe size 24?, What is EU shoe size 25?, What is EU shoe size 26?, What is EU shoe size 27?, What is EU shoe size 28?, What is EU shoe size 29?, What is EU shoe size 30?, What is EU shoe size 31?, What is EU shoe size 32?, What is EU shoe size 33?, What is EU shoe size 34?, What is EU shoe size 35?, What is EU shoe size 36?, What is EU shoe size 37?, What is EU shoe size 38?, What is EU shoe size 39?, What is EU shoe size 40?, What is EU shoe size 41?, What is EU shoe size 42?, What is EU shoe size 43?, What is EU shoe size 44?, What is EU shoe size 45?, What is EU shoe size 46?, What is EU shoe size 47?, What is EU shoe size 48?, What is EU shoe size 49?, What is EU shoe size 50?.

Example for the conversion of the US shoe size

Ms Miller wants to buy new shoes and has US shoe size 8. Using the shoe size converter, she calculates the sizes of the other shoe size systems, i.e. the EU size, the UK size and the Mondopoint size, based on her US shoe size.

1. Calculating Ms Miller's foot length from her US size.

First, the foot length is calculated using the US shoe size 8. The foot length is then used as the basis for calculating the EU, UK and Mondopoint sizes. For this purpose, the ISO formula for calculating the US shoe size is broken down according to the foot length, i.e. converted.


ISO formula for calculating the US size for ladies

US women's shoe size = (foot length + 2 × 0.847) / 0.847 − 23

Explanations

  • One US size is equal to one third of an inch, therefore 0.847 cm.
  • The first 11 US sizes are not numbered.
  • The following 13 sizes are assigned as children's sizes
  • The American shoe sizes for women start with size 0 after the children's sizes.
  • Therefore, 23 sizes are subtracted in total
  • In addition, two US shoe sizes toe clearance, i.e. 2 × 0.847 cm are added on

Converted US formula for calculating foot length

foot length in cm = (UK shoe size + 23) × 0.847 − 2 × 0.847

Calculation of Ms Miller's foot length

(8 + 23) × 0.847 − 2 × 0.847 = 24.56 cm

Using this foot length, the shoe size for the other size systems is now calculated using the appropriate ISO formula.

2. Calculate EU size based on the determined foot length

To determine Ms Miller's EU size, the appropriate ISO conversion formula is first used based on her foot length. Then the result of this calculation is rounded to the nearest whole or half size.

Formula for EU size

EU shoe size = (foot length in cm + 2 × 0.667) / 0.667

Explanations

  • One size equals two-thirds of a centimetre, i.e. 0.667 cm
  • Sizes start at 0
  • Two sizes of toe clearance are added on, so 2 × 0.667 cm.

Here you can find more detailed information on EU shoe sizes.

Calculation of the EU size

(24.56 cm + 2 × 0.667) / 0.667 = 38.826 EU

Rounding the result

Rounded to the nearest whole or half size, this gives Ms Miller Size 39.0 EU.

Ms Miller's US shoe size 8 for women corresponds to EU size 39.

3. Calculate UK shoe size using Mrs Miller's calculated foot length.

To calculate Ms Miller's UK size, the appropriate ISO conversion formula is first used based on her foot length. The result of the calculation is then rounded to the nearest whole or half size.

We can already reveal at this point that Ms Miller's UK shoe size is 6.0. According to the ISO standard, UK shoe sizes are always two sizes smaller than the US shoe size, in Ms Miller's case two sizes smaller than her US size 8. In this respect, it is not surprising that the application of the ISO formulas ultimately comes to this result, which you can also check in the following.

ISO formula for UK size

UK shoe size = (foot length + 2 × 0.847) / 0.847 − 25

Explanations

  • One size equals one third of an inch, i.e. 0.847 cm
  • The first 12 sizes are not numbered
  • The following 13 sizes are children's sizes
  • Adult sizes start with size 1 following the children's sizes.
  • 25 sizes are therefore subtracted
  • Two sizes of toe clearance, i.e. 2 × 0.847 cm are added on

Here you can find more comprehensive information on UK shoe sizes.

Calculation of the UK size

(24.56 cm + 2 × 0.847) / 0.847 − 25 = 6.0 UK

Rounding the result

Rounded to the nearest whole or half size, this leaves Ms Miller Size 6.0 UK.

Ms Miller's US shoe size 8 for women corresponds to UK size 6 after conversion.

4. Calculate Mondopoint shoe size to Mrs Miller's foot length

Converting foot length to the Mondopoint system is rather easy because Mondopoint sizes indicate foot length in millimetres.

ISO formula for Mondopoint size

Mondopoint ;size = foot length in cm × 10

Here you can find more detailed info on Mondopoint shoe sizes.

Calculation of the Mondopoint size

24.56 cm × 10 = 245.6 Mondopoint

Rounding the result

Rounded to the nearest Mondopoint size, this gives Ms Shoemaker size 245 Mondopoint.

Ms Miller's US shoe size 8 for women corresponds to Mondopoint size 245 after conversion.

Source information

As source for the information in the "Sizes of shoe" category, we have used in particular:

Last update on May 10, 2021

The last changes in the "Sizes of shoe" category were implemented by Stefan Banse on May 10, 2021. The main changes were: