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Shoe Size Converter

Converters · Added

Every sizing system in use is defined arithmetically, so this computes rather than looks up: Japanese sizes are the foot length in centimetres, EU sizes count Paris points of two thirds of a centimetre, and UK and US sizes count barleycorns of a third of an inch. The gap between the foot and the shoe's last is an input, because it is a manufacturer's choice and it is where brands disagree.

Heel to longest toe

How much longer the shoe's last is than the foot. It is a manufacturer's choice, and it is the single biggest reason two brands label the same shoe differently.

How to use the shoe size converter

  1. 1Pick the system you already know your size in — or measure your foot and choose one of the length options.
  2. 2Enter the size or the measurement.
  3. 3Adjust the last allowance if you know whether the shoes run close or roomy.
  4. 4Read the converted sizes, and use the surrounding table to see the sizes either side.

Examples

From a foot measurement

Input
26 cm foot length
Result
UK 7.5 · US men's 8.5 · US women's 10 · EU 41.5

From a known EU size

Input
EU 42
Result
Foot length about 26.5 cm · UK 8 · US men's 9

About the shoe size converter

Three systems, three units of length

The barleycorn behind UK and US sizes is a third of an inch, and it is a medieval English unit: three barley grains laid end to end. Sizes count upwards from a fixed origin, which is why a UK size has to be converted through a length rather than by adding a constant.

The Paris point behind EU sizes is two thirds of a centimetre, which makes EU sizes coarser than UK ones — roughly one and a half EU sizes to one UK size. That mismatch is why the two scales cannot be aligned exactly and why conversion charts disagree at the edges.

Mondopoint, used in Japan and in every technical standard, sidesteps the problem by measuring the foot in millimetres. It is the only one of the three that describes the wearer rather than the product, which is why it is what ski boots and military footwear are specified in.

Why online sizing goes wrong

The usual failure is converting twice. A shopper knows their UK size, a chart converts it to EU, the retailer's own chart converts that back to their internal sizing, and each step rounds to the nearest half. Two roundings in the same direction is a full size.

The way out is to work from the length. If a retailer publishes the foot length each of their sizes fits — many now do — compare against that figure directly and ignore the size numbers entirely.

Frequently asked questions

Why does this ask about a last allowance?
Because the UK, US and EU scales all measure the last — the form a shoe is built on — rather than the foot, and the last is longer than the foot by however much room the maker decided to leave. That figure is typically between one and one and a half centimetres, it is a design decision rather than a standard, and it is the single largest reason two brands label the same shoe differently.
Will these sizes fit me in any brand?
No, and no conversion can promise that. Length is one dimension of three: width, instep volume and toe-box shape all vary between lasts, athletic and dress lasts differ inside a single brand, and half a size of disagreement between makers is ordinary. Treat the result as which pair to try first.
How should I measure my foot?
Standing, with your weight on it, on a sheet of paper against a wall — heel to the wall, mark the longest toe, measure the distance. Do it late in the day, when your feet are at their largest, and measure both: a difference of half a size between the two is common, and the larger foot is the one to size for.
Why are children's sizes not covered?
Because the UK and US children's scales restart from zero on their own numbering, so a child's 12 and an adult's 12 are entirely different shoes. Converting between the adult and children's scales needs the crossover point, which differs by market. This tool covers the adult range and refuses anything outside it rather than extrapolating into a system it does not implement.

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