US shoe sizes - American shoe sizes and their conversion

The US Shoe Size Converter converts any of US shoe size into other 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 men and women. In addition, US sizes are calculated for children and babies.

An example of the calculation of US shoe sizes

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

The US shoe size system (such as the British) is based on the inch (2.54 cm) unit of length. Also, in North America, each shoe size 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 Size 1 for men. 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 as well as the interior length, or the length of the shoe last. This is one of the reasons why shoe sizes greatly vary.

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

The US Shoe Size Calculator determines the 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. Therefore, shoes are often smaller or larger than the assumed on the basis of the size (depending on the manufacturer, or due to deviating standardisations).

ISO formula for calculating the US shoe size for men

The formula for US men's sizing makes it clearer that each size equals 0.847 cm. For the toe room, two sizes are added, i.e., 2 × 0.847 cm. Finally, 24 sizes are subtracted from 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 more size is allocated for the same foot length.

ISO formula for calculating the US shoe size for women

The formula for US women's sizing shows that each size equals 0.847 cm. For the toe room, two sizes are also added here, i.e., 2 × 0.847 cm. 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. This is because 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 as described above.

ISO calculation formula for US shoe size for children

Compared to the adult formula, a surcharge of 8 percent of the foot length is added for the toe clearance, instead of the two English sizes. However, only 11.5 instead of 12 "empty" sizes are deducted at the beginning compared to the UK children's size, such that the US children's sizes are always 0.5 sizes and above of 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 tables are the results for all American shoe sizes. Unlike the other shoe-size systems, US shoe sizes distinguish 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

Printable US size chart for adults

US Shoe Size Chart for Children's US Sizes

In the USA and the UK, children­shoe­sizes are assigned different numbers than adults in terms of shoe sizes. After a total of 13 US children’s shoe sizes, the US adult shoe sizes 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
4	4.7	12.0	120	19.5	3.5
4.5	4.8	12.3	125	20	4
5	5.0	12.7		20.5	4.5
5.5	5.1	13.0	130	21	5
6	5.2	13.3		21.5	5.5
	5.3	13.5	135	22
6.5	5.4	13.8	140	22.5	6
7	5.6	14.2		23	6.5
7.5	5.7	14.6	145	23.5	7
	5.8	14.8		24
8	5.9	15.0	150	24.5	7.5
8.5	6.1	15.4	155	25	8
9	6.2	15.7		25.5	8.5
9.5	6.3	16.0	160	26	9
	6.4	16.4		26.5
10	6.5	16.6	165	27	9.5
10.5	6.7	16.9	170	27.5	10
11	6.8	17.3		28	10.5
11.5	6.9	17.6	175	28.5	11
12	7.0	17.9	180	29	11.5
	7.2	18.2		29.5
12.5	7.3	18.5	185	30	12
13	7.4	18.8		30.5	12.5
13.5	7.6	19.2	190	31	13
1	7.7	19.5	195	31.5	13.5
	7.8	19.8		32
1.5	7.9	20.0	200	32.5	1
2	8.0	20.4	205	33	1.5
	8.1	20.7		33.5
2.5	8.3	21.0	210	34	2
3	8.4	21.3		34.5	2.5
3.5	8.5	21.7	215	35	3
4	8.7	22.0	220	35.5	3.5
	8.8	22.4		36
4.5	8.9	22.6	225	36.5	4
5	9.1	23.0	230	37	4.5
	9.1	23.2		37.5
	9.3	23.6	235	38	5
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 is yet to determine a corresponding size in the other size units 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.

Printable US 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, for example, EU Shoe Size 38, 42 or 43, you can either use the Shoe Size Converter, or use the matching shoe-size chart, or check 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?.

An example of the conversion of the 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).

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.

Ms Miller's US Shoe Size 8 for women corresponds to EU Size 39.

3. Calculate UK shoe size using Ms 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 twice smaller than the US shoe size. In Ms Miller's case, two sizes are smaller than her US Size 8. In this respect, it is not surprising that the application of the ISO formulas finally comes to this result, which you can also check below.

Ms Miller's US Shoe Size 8 for women corresponds to UK Size 6 after conversion.

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

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

Ms Miller's US Shoe Size 8 for women corresponds to Mondopoint Size 245 after conversion.