Brand Shoe Size Differences

The headline centimetre barely differs

Line the three big brands' own charts up at the same US size and they agree.

Every one steps a clean 0.5 cm per half size. At the level of the number on the box, a 27.0 in one brand is a 27.0 in the next. If brands felt different to you, the cause is not this number, so it is worth knowing what does move.

The centimetre on the box is not your foot length

The first real gap is between the label and the foot it fits. Both Nike and adidas publish a second, quieter number: the actual foot length each size is designed for. On Nike's chart a 27.0 cm shoe fits a 26.2 cm foot, and on adidas's it fits a 26.3 cm foot. The label runs about 0.7 to 0.8 cm longer than the foot, built-in ease so the toes are not pressed to the end.

This is the same convention Japanese sizing uses on purpose: a cm label already carries about a centimetre of toe room. So if you measure a 26.2 cm foot and buy a shoe stamped 26.0 because the numbers look close, it will be short. Match your foot length to the brand's fitted-foot column, not to the label.

Where the brands round to Europe differently

The second real gap is the European number. At US 9, Nike's chart prints EU 42.5, while adidas prints EU 42 2/3, because adidas grades in Continental thirds of a size. The standards-based conversion this site uses puts US 9 at EU 42. Three sources, three European numbers for one US size, none of them wrong, each a different rounding of the same foot. When you cross from a US or UK number to a European one, the half-size you land on depends on whose chart did the rounding.

adidas adds a further wrinkle: it builds on a UK last, so its scale steps as UK equals US minus a half. A US 9 is a UK 8.5 on adidas, which is why an adidas box can show a UK number that looks half a size off from an American chart. Nike prints that same US 9 as a UK 8, so even the British number for one foot splits by half a size between the two brands.

Where brands differ most: width

The largest real difference between brands is not length at all, it is width, and here the charts diverge sharply. Width is a girth measurement around the ball of the foot, and brands neither offer the same widths nor place them the same.

New Balance Japan lists four men's widths, D, 2E, 4E and 6E, and treats 2E rather than D as its standard men's fitting, noting that only two or three are made for any given model. ASICS runs its own tiers, NARROW, STANDARD, WIDE and EXTRA WIDE, and its standard is cut wider than the national table: at a 25.0 cm foot the ASICS standard 2E has a 255 mm girth, exactly what the Japanese JIS table calls 3E. In other words an ASICS shoe fits about one full width step roomier than a JIS chart would predict. A person who is a JIS 2E can be an ASICS E. Two shoes of the same length and the same width letter, from these two brands, are not the same girth.

Model-level fit is mostly folklore

Retail lore says a given model "runs small" or "runs large," but the official charts do not. Nike, adidas and New Balance each publish one universal size table with no per-model offset; Nike's only note is the generic "if you are between sizes, size up." Claims that a particular running line runs half a size long, or that a particular classic runs large, come from reviews and shops, not the brand's chart. Independent lab measurement bears this out from the other side: one review site measured the inside length of adidas shoes all labelled US 9 and found it ran from 260 to 280 mm across models, a 20 mm spread the official chart never shows. Treat model lore as useful hearsay to check against a fitted-foot measurement, not as published fact. The one model difference the brands do state is between men's and women's lasts: the same model and size fits differently by gender because the shape, not the length, changes.

How to use all this

Because the headline cm agrees but the foot behind it does not, work from your own measurement:

1. Measure your bare foot length in millimetres, at the end of the day.
2. Match it to the brand's fitted-foot column, not the box label, allowing for the 0.7 to 0.8 cm of ease.
3. Check the width the model offers, since an ASICS or New Balance wide is a real girth difference, not a bigger number.
4. For the neutral cross-system conversion, use the men's and women's charts, which convert from foot length by the standard rather than any one brand's rounding.

See also the shoe width guide for the girth numbers behind the letters, and the foot-length guide for the measurement itself.

Frequently asked questions

Do shoe brands size differently?

Less than people think. Nike, adidas and New Balance all call a US 9 a 27.0 cm shoe. The real differences are the ease built into the label, the European rounding, and the width.

Why does the cm on the box not match my foot?

It is not meant to. The label runs about 0.8 cm longer than the foot it fits, so a 27.0 cm shoe suits about a 26.2 cm foot. Match your foot to the fitted-foot column.

Why do Nike and adidas give different EU sizes for the same US size?

They round differently. At US 9, Nike prints EU 42.5 and adidas EU 42 2/3, while the standard conversion is EU 42. All three describe the same foot.

Is an ASICS wide the same as a New Balance wide?

No. Width is a girth, and brands cut it differently. ASICS runs about one step wider than the Japanese national table, so its letters do not match another brand's.

Does a model run small or large?

The official charts show no per-model offset, so "runs small" is retail lore, not published fact. Check it against a fitted-foot measurement rather than trusting it.