China shoe size conversion: CN to US, EU and UK

Measure your foot the way a factory does

Stand on a sheet of paper with your heel against a wall. Mark the tip of your longest toe. Measure from the wall to the mark in centimetres. Do it in the evening, because feet swell during the day, and do it standing, because your foot is longer under load.

Measure both feet and use the longer one. Most people differ by a few millimetres, and the larger foot decides the size. Write the number down in centimetres with one decimal place. That number is your key to every listing.

• Measure in the evening, not in the morning
• Stand up, do not measure a seated foot
• Use the longer foot
• Round up to the next half centimetre for thick socks
• Re-measure if your weight or activity changed

The conversion table

The table below is keyed on foot length because that is the number published on the listing and the number you control. CN sizes on Chinese platforms most often follow the European scale, which is why CN 42 and EU 42 usually mean the same thing there.

US and UK columns are given for men. Women's US sizes are typically 1.5 larger than men's for the same foot length, and UK sizing sits about half a size below US.

Why the same number fits differently

A last is the mould a shoe is built on. Two brands can both call a shoe a US 9 and cut one narrow with a long toe box and the other wide with a short one. That is why a person who wears a 9 in one sneaker needs a 9.5 in another.

For rep listings the question is not only the brand but the factory's version of the last. Ask the seller for the internal length of the insole in centimetres if it is published, and compare it with your foot length plus about 0.5 cm of clearance.

Width and volume

Chinese and EU width scales are usually one width, which is narrower than a US standard width in many brands. If you normally wear a US wide, this is the detail that will bite you, not the length.

There is no clean conversion for width on most listings. The practical move is to go up half a size and accept a little extra length for the volume you need, or to pick a silhouette known for a roomier toe box.

Boots, heels and the awkward categories

Boots usually run true to the last but need extra room for a thicker sock. A boot that fits perfectly with a thin sock will be unwearable in winter. Size for the sock you will actually wear.

Heels are the hardest. The last is narrow and the toe box is short, so people often need a full size up compared with their sneaker size, and the heel still may slip. If a heel is important to you, order one and treat the sizing as an experiment you will pay for once.

Verify before the parcel leaves

Ask the agent for a photo of the size label and, if possible, the insole length. Many warehouses will do this as part of inspection if you ask clearly. It takes a day and it catches the listing that shipped the wrong size.

Add the insole length to your spreadsheet next to the size you ordered. After a few pairs you will know exactly how that seller runs, and the guesswork disappears. The oopbuy style size log keeps brand, size, insole length and verdict in one row.

When the chart is still wrong

Even a good chart can miss, because the shape of the last matters as much as the length. Two shoes with the same insole measurement can fit differently across the toe box or at the heel. That is why one size can feel tight in a pointed silhouette and roomy in a round one, with no error on either side.

If you are between sizes, take the larger one for anything with a pointed toe or a narrow last, and the smaller one for a round toe with a generous box. It is a rule of thumb rather than a law, but it beats picking the number that matches the sneakers you already own, which were probably built on a different last entirely.