Three ways to count a size
Every size system counts steps from a starting length. They differ in the step, in where they start, and in what they measure: the last (the form the shoe is built on) or the foot. Here is one 26 cm foot in each, on the standard tables.
| System | 26 cm foot | Foot per size | Unit | Counts |
|---|---|---|---|---|
| US men’s | 9 | 8.5 mm | Barleycorn, ⅓ inch | The last, by custom |
| US women’s | 10.5 | 8.5 mm | Barleycorn, ⅓ inch | The last, by custom |
| UK | 8 | 8.5 mm | Barleycorn, ⅓ inch | The last |
| EU | 41 | 6.7 mm | Paris point, ⅔ cm | The last |
| Mondopoint | 260 | 5.0 mm | Millimetre (5 mm steps) | The foot |
| Japan | 26 | 5.0 mm | Centimetre (½ cm steps) | The foot |
Foot per whole size from the standard tables (a half size is half that); for Mondopoint and Japan, per step of the table. Which country uses which: shoe sizes by country.
US and UK: the barleycorn
A barleycorn is an old English unit of ⅓ inch, and it is still the step between UK and US sizes. A medieval English statute defined the inch as “three grains of barley dry and round”; the idea is older still, in the 10th-century Welsh laws of Hywel Dda. You may read that King Edward II invented shoe sizes in 1324: there’s no evidence he set any shoe standard.
The first recorded British sizing system, in Randle Holme’s Academy of Armoury (1688), used quarter inches. Third-inch steps are documented next, probably from 1856, in Robert Gardiner’s handbook of the foot. In the US, New York businessman Edwin Simpson introduced a detailed system in 1880, built on the barleycorn, and the industry adopted it about a decade later; half sizes appeared in 1887.
UK children’s sizes run 0 to 13.5, then adult sizes start again at 1; US children’s sizes run 0C to 13.5C, then youth sizes start at 1Y. Why children’s sizes stop at 13 has been lost: SATRA says the usual explanations “may well be fanciful”. On a Brannock device a men’s size 1 is 7⅔ inches and each size adds ⅓ inch, as on the standard table, where a men’s 1 fits 19.5 cm of foot.
The shop gauge, and its women’s scale: reading a Brannock device.
EU: the Paris point
Continental Europe counts Paris points of ⅔ cm, a unit fixed in France around 1800. One scale serves men, women and children. An EU size is the length of the last, not the foot: the last is typically 13–17 mm longer than the foot, about two sizes. A Paris point (6.7 mm) is smaller than a barleycorn (8.5 mm), so EU sizes are closer together and never line up exactly with UK or US ones.
Mondopoint: the foot in millimetres
The International Organization for Standardization introduced Mondopoint in 1973 (ISO 2816), replaced it with ISO 9407 in 1991, and revised it in 2019. Mondopoint sizes a shoe by the foot it should fit: the foot length in millimetres, and sometimes the width. Japan (JIS S 5037), China and Korea use it, Japan in centimetres, and the sports industry uses it widely, for ski boots in particular.
Ski boot sizes in Mondopoint.
Why the numbers don’t line up
Each system starts somewhere different and steps by a different amount, so a conversion is a lookup, not a fixed offset. On the standard tables US men’s sizes are 1 above UK and US women’s 2½ above, but brands round differently: Nike’s and adidas’ charts put US men’s only ½ above UK at small sizes, and Converse’s Chuck Taylor chart makes them equal. Women’s sizes sit 1 to 2 above men’s depending on the brand (men’s vs women’s sizes).
ISO 19407 (2023) publishes conversion tables starting from foot length, but says the systems developed “over many years without being formalized”, so its tables are a guideline. Clarks puts it plainly: “there is no true conversion available.”
Every conversion, size by size: shoe size converter.
Why brands differ
Even within one system, brands measure differently, make shoes differently and leave a different allowance between foot and last. On their own charts, the 23 brands that print a foot length for a men’s US 9 give feet from 26.0 cm (HEYDUDE) to 27.7 cm (Golden Goose); the standard table says 26.3 cm. That’s 4 half sizes from end to end.
- 26.0 cm HEYDUDE
- 26.0 cm KEEN
- 26.2 cm Reebok
- 26.2 cm Jordan
- 26.2 cm Nike
- 26.3 cm adidas
- 26.3 cm ANTA
- 26.3 cm Clarks
- 26.4 cm HOKA
- 26.4 cm SOREL
- 26.5 cm Salomon
- 26.9 cm UGG
- 27.0 cm Saucony
- 27.0 cm Dr. Martens
- 27.0 cm Fila
- 27.0 cm Liberty
- 27.0 cm New Balance
- 27.0 cm Timberland
- 27.0 cm Under Armour
- 27.0 cm Vans
- 27.0 cm Zara
- 27.4 cm Teva
- 27.7 cm Golden Goose
Labels add to it. The CM size on a box isn’t always the foot: Nike notes its box CM “is different than Foot Length (cm)”. And as Brannock tells fitters, manufacturing and styling vary, so two shoes of the same size can still fit differently.
Questions
Why are shoe sizes so confusing?
Because there are several systems, counted in different units (barleycorns, Paris points, millimetres), starting at different lengths, some counting the last and some the foot; and brands set their own tables within each.
What is a barleycorn in shoe sizes?
An old English unit of ⅓ inch (8.5 mm), the step between whole UK and US sizes.
Did Edward II invent shoe sizes?
A medieval statute did define the inch as three barleycorns, but there is no evidence that Edward II set a shoe-size standard. The first recorded British sizing system is from 1688.
Is there a universal shoe size?
Mondopoint (ISO 9407) is the international standard: the foot length in millimetres. Ski boots and Japanese, Chinese and Korean shoes use it; most everyday shoes elsewhere still use US, UK or EU sizes.
Why does my size differ between brands?
Brands set their own lasts and size tables. On their charts, a men’s US 9 fits feet from 26.0 to 27.7 cm. Read each brand’s chart by your foot length.