A Grain Of Barley: Why Shoe Sizes Never Agree

The number inside your shoe is seven hundred years old and describes a wooden form, not your foot. From a medieval decree about grains of barley to the metric system nobody adopted, here is how the world ended up with four shoe sizing systems that refuse to agree.

The number printed inside your shoe is about seven hundred years old, and it was never really about your foot. It describes a wooden form, in a unit taken from a grain of cereal, fixed by a medieval king who had nothing to do with shoes. Everything confusing about buying footwear online follows from that.

A grain of barley, 1324

Before the fourteenth century, English measurement was local and approximate. A Saxon foot ran to thirty-nine barleycorns. Cross into Wales and a foot was twenty-seven. Merchants complained, as merchants do, and in 1324 Edward II issued a decree fixing the inch as the length of three grains of barley, dry and round, placed end to end.

That gives the barleycorn: one third of an inch, about 8.5 millimetres. It is the ancestor of every UK and US shoe size in use today.

Edward is usually credited with inventing shoe sizing at this point. He did not. He standardised a unit, and shoemakers borrowed it centuries later. The first written description of sized shoes appears in Randle Holme's Academy of Armory and Blazon of 1688, and it steps in quarter inches, not barleycorns. The system we would recognise, counting in thirds of an inch, is not described until Robert Gardiner's Illustrated Handbook of the Foot in 1856. More than five centuries separate the unit from its use.

Why the numbers start where they do

The English scale begins at a child's size 0, set at a last four inches long, roughly a newborn's foot. Each size adds one barleycorn. Children's sizes climb to 13 and a half, and then the count resets: adult size 1 starts again at eight and two thirds inches.

That reset is the whole reason adult shoe sizes look arbitrary. A UK 9 is not nine of anything. It is thirty-four barleycorns of last length, carrying a label left over from a counting sequence that restarted in the middle.

France goes metric, in its own way

French shoemakers in the early 1800s wanted nothing to do with barley. They built their own unit, the Paris point, at two thirds of a centimetre, or 6.67 millimetres.

It looks like a clean metric choice and mostly is not. Two thirds of a centimetre happens to sit very close to a quarter of the old French pouce-roi, the pre-revolutionary inch. The Paris point is a metric number chosen to land near the measurement everyone already had in their hands.

This is why continental sizes step in units of 6.67 millimetres while British ones step in 8.5, and why the two scales will never line up. Converting between them always leaves a remainder, and every brand disposes of that remainder differently.

America keeps the unit, moves the starting line

American sizing grew directly out of the English system and kept the barleycorn. What it changed was where the count begins. That single decision is why US sizes sit roughly one size off their UK equivalents, a gap that has quietly confused shoppers on both sides of the Atlantic ever since.

Japan took the opposite approach and simply used the length of the foot in centimetres, which is why Japanese labels are the easiest in the world to read.

The system built to fix all of this

In the 1970s the International Organization for Standardization introduced Mondopoint. The name is from mondo, world. It gives foot length in millimetres, often with width as well, and it describes the wearer instead of the mould. It is unambiguous, it is genuinely international, and it is the obvious answer.

Almost nobody uses it. Ski boots and several militaries adopted it. Retail did not.

The reason is not stubbornness so much as steel. A shoe is built over a last, and factories hold enormous inventories of lasts, cutting dies and tooling calibrated to legacy increments. Converting the industry to a clean metric scale would mean replacing that tooling worldwide, in a business that runs on thin margins. Add to that a customer who has worn an 8 for thirty years and has no interest in becoming a 265, and the incentives point firmly at leaving things alone.

So four systems persist, and your shoes are stamped with two or three of them.

What that means when you are choosing a pair

Take four brands we stock, at a size a lot of Australian men wear. A US 11 is an EU 44 in VEJA, an EU 44.5 in Vans, an EU 45 in Saucony and an EU 45 and a third in HOKA.

Each is being consistent with its own history. VEJA is French and grades natively in Paris points, skipping 44.5 altogether. Vans works from foot length in centimetres and converts outward, which is why its European numbers land on halves that a true Paris point grade could never produce. Saucony, American since 1898, grades in barleycorn sizes and converts the other way, which is why its US 6 is an EU 38.5 rather than the 38 you would expect. HOKA grades in true Paris points, in thirds, which is why there is no such thing as a HOKA EU 45.

Even foot length does not fully settle it. At a US 11, VEJA and HOKA put you at roughly 28 centimetres of foot, while Vans and Saucony say 29. A full centimetre of disagreement about which foot a number is for, because the last matters as much as the scale.

So measure your foot

Not your shoe. Your foot.

Stand on a sheet of paper with your heel against a wall. Mark the tip of your longest toe, which is not always the big toe. Measure from the wall to the mark in centimetres. Do both feet and use the larger, since almost everyone has one bigger than the other. Do it in the afternoon, once your feet have swelled slightly, because that is the state they will be in for most of the hours you wear the shoes.

One number, measured once, that you can carry to any chart. It will not tell you your size. It will tell you where to look on the only chart that matters, which is the one belonging to the brand in front of you.

What we're doing about it

Every footwear size guide on this site shows that brand's own published conversion rather than a generic one, with foot length alongside it. Where a brand does not publish a conversion, we leave it out rather than estimate it. A guessed size is worse than an honest gap.

If you are between sizes, or a particular brand has caught you out before, email us. We have the stock in front of us and we are happy to measure a pair.