Why One Foot Length Gives Many Shoe Sizes

The foot is shorter than the shoe

Every shoe is longer inside than the foot that wears it, to leave the toes room as the foot slides forward in each step. For adults that allowance is about 1.0 to 1.5 cm on top of the measured length. Children's fitting rules make it explicit and larger, asking for 12 to 17 mm of growing room, because a young foot needs the space to lengthen between one pair and the next. A bare foot length is never the inside length of the shoe. It is the raw number that each national system then treats in its own way.

What a size number counts

A shoe number points at one of two objects: your foot, or the last, the foot-shaped form the shoe is moulded around. That single choice explains most of the disagreement between charts. Systems built on the foot print the length you would measure at home and leave the toe room as space you cannot see. Systems built on the last print a number for the form, which already runs longer than the foot, so the room is carried inside the number itself. Converting between the two is a translation, not arithmetic.

Europe counts the last, not the foot

The European number is worked out from the last, not from the foot. One European size is two thirds of a centimetre, a unit called the Paris point that France fixed around 1800. Because the last is cut longer than the foot to hold the toe room, the European number describes a form up to about 1.5 cm longer than your foot. That is why a European chart and a centimetre chart drift apart as sizes climb: they are measuring two different objects, and the gap between them grows with every step.

The same European number, a narrower last

Even inside Europe one number covers more than one shoe. Italy and France print the same figure on the box, so an Italian 42 and a French 42 share a scale on paper. The lasts do not match. French brands are cut on a narrower form, so the same 42 grips a wider foot, and buyers often move up a size in a French label to get the width back. The number agreed while the shape did not, which is the small local version of the worldwide problem, between two neighbours that are meant to share one system.

Japan counts the foot and adds the room

Japan takes the other route. A Japanese label is the foot length in centimetres, so a 26.0 is made for a 26 cm foot, the same number a Mondopoint chart would give. The room lives in the shoe rather than the number: makers add a toe allowance called sutesun, so a shoe printed 23.0 measures around 24 cm inside. The label matches your foot while the shoe runs about a centimetre longer. A Japanese 24 marks a foot and a European 24 marks a last, so the two describe different shoes even though the figure looks the same.

Asia is more than one column

Charts flatten Asia into a single column, yet the region runs several systems. China uses three at once: an older domestic scale, a metric scale in centimetres set by GB 3293, and a world scale in millimetres, required on boxes since the late 1990s and written as foot length over foot width, something like 260/94. The three tie together by formula. The new centimetre size is the old number plus ten, halved, and the world millimetre size is the centimetre size times ten, so an old 40 resolves to 25 cm and 250 mm. A mainland box must carry the new or the world number, which is why a Chinese shoe can show a figure that looks nothing like the EU one printed beside it. Korea took the cleaner route and labels in millimetres in 5 mm steps, 250, 255, 260, the Mondopoint idea applied to the whole shelf. Like Japan and the post-Soviet states, both name the foot, so the room stays inside the shoe.

America and Britain size the last in barleycorns

The US and UK scales also count the last, using an older English unit. One size is a barleycorn, a third of an inch or about 8.5 mm, a grain-based step that carried over from cloth measure into the shoe last. The Brannock device on the shop floor reads your foot, then works in the allowance the last carries, close to two barleycorns or about 1.7 cm, before it settles on a size. An American number, like a European one, therefore sits ahead of the bare foot. Its step is wider than the European two thirds of a centimetre, which is part of why the two scales never line up across the whole range.

Eastern Europe stamps the foot in millimetres

Russia and other post-Soviet countries use the metric system in GOST 11373-88, where the size is the foot length in millimetres, in 5 mm steps. That is the 270 you can find stamped inside a boot from the region, next to the European number. Like Mondopoint, the Japanese cm and the Korean millimetre, it names the foot, so the shoe around it is built longer. Several of these systems point at your foot, while the European and the English ones point at the last, and that split is the reason a single measurement scatters into different numbers.

The size hides a second measurement

A length number leaves out the other half of fit. Two feet the same length can differ by more than a centimetre around the ball of the foot, and a shoe that is right end to end can still pinch or swim. Japan writes this into the size. JIS grades width by ball girth, so a 25 cm men's foot runs the girths below, each grade adding about 6 mm.

ASICS builds its own ladder a step wider, where its E equals a JIS 2E, so the same letter is not the same width across two Japanese makers. Germany runs a parallel width ladder from F upward, and China's world number carries the width outright as the second figure in 260/94. English and American sizing answers width with a single letter, D or E, when it answers at all. A conversion chart that gives you one number is dropping the measurement that decides whether the shoe fits across, not only along. The full width story is in the shoe width guide.

Converting a centimetre measurement without guesswork

Measure the bare foot standing, late in the day, and treat that centimetre figure as your foot, not your shoe. To reach a regional size, read the number that region prints for that foot instead of adding or subtracting across systems. In our catalog a 26 cm foot is a men's EU 41, US 8 and UK 7, and a women's EU 40.5, US 9 and UK 7, the gender gap coming from the separate scales that men's and women's shoes use for the same length. A 27 cm foot is a men's EU 42 and US 9. Where a size falls between two, the wider foot and the roomier shoe take the larger.

• CM to US (Men)
• CM to US (Women)
• CM to US (Kids)
• What is Mondopoint?
• How to measure foot length
• Brand size differences

Frequently asked questions

Why does a 26 cm foot give different shoe sizes?

Because the systems count different objects. Mondopoint, the Japanese cm, the Korean millimetre and the GOST metric number all name the foot, while the European and the US or UK numbers name the last, which sits longer than the foot. The same 26 cm is a men's EU 41 and a women's EU 40.5 in our catalog.

What is the number stamped inside my shoe?

A metric number like 270 is the foot length in millimetres, from GOST or the Mondopoint family. A Chinese box may show two numbers, foot length over foot width, as in 260/94. A plain cm figure on a Japanese shoe is the foot it is built for, with about a centimetre of room added inside.

Why do Chinese sizes sometimes have two numbers?

The world system China requires writes foot length over foot width in millimetres, so 260/94 means a 260 mm foot and a 94 mm width. It carries the width the European number leaves out.

Is my centimetre size the inside length of the shoe?

No. A centimetre or Mondopoint size is the bare foot length. The shoe is made about 1.0 to 1.5 cm longer for adults so the toes clear the front.

Should I size up when I convert from centimetres?

Not by default. If you measured the bare foot, the target system already carries its own allowance, so a straight read is right. Go up only when your measurement lands between two sizes, or when your foot is wide.

Which number should I trust?

The one the maker prints for your region, checked against that brand's own chart. Treat a cross-system conversion as a starting point, since the brand controls the last, the width and the fit.