Shoe Size Converter

A shoe size converter translates a size from one country's system into another. Type in your size, pick who the shoe is for, and this converter shows the matching US, UK, EU, and CM size in one table. Every row is anchored to foot length in centimeters, so the four numbers always describe the same foot.

Use it when you shop on an international site, read a size chart in a different system, or check whether a brand's EU size matches the US size you know. The converter covers men's, women's, and kids' shoes. It also handles the tricky cases, like an EU size that covers two US half sizes and kids' size numbers that repeat in toddler and youth sizing.

Four systems, four ways of naming the same foot length. The US system grew out of the old English barleycorn scale, where one full size equals 1/3 inch (0.85 cm) of foot length, and sizes step in halves. The UK system uses the same 1/3 inch step but starts counting from a different zero point, so the numbers never match the US ones. The EU system is metric. It counts in Paris points, where one size equals 2/3 cm, and it steps in whole numbers only. The CM system is the simplest of all. It is the Mondopoint base defined in ISO 9407, and it just states your foot length in centimeters.

This converter works by table lookup. Your entry is matched to the chart row with the same size, or to the nearest row when you enter foot length in cm. The whole row is then read out, so US, UK, EU, and CM all describe the same foot. The chart behind the tool comes from the published calculator.net size tables, which were cross-checked against two more independent charts. Brands still cut shoes on different lasts, so treat any conversion as a strong starting point and check the brand's own chart before you buy.

Take a men's US 9, a common size to convert. The converter finds US men's 9 in the chart, where it sits on the 26.2 cm foot length row. The same row reads UK 8 and EU 41. So a men's US 9 converts to UK 8, EU 41, and 26.2 cm.

You can check this against the system's own math. The US men's formula is size = 3 times foot length in inches minus 22. A 26.2 cm foot is 10.31 inches, and 3 times 10.31 minus 22 is 8.93, which rounds to 9. The EU formula is size = 1.5 times cm plus 2, and 1.5 times 26.2 plus 2 is 41.3, which rounds to EU 41. Both formulas land on the same row.

Getting a conversion takes five short steps.

1. Choose who the shoe is for. Pick men, women, or kids.
2. Pick the system your size is in. Choose US, UK, EU, or CM foot length.
3. Pick the system you want to convert to, or leave the default. The swap button flips the two systems.
4. Type your size. For CM, type your foot length in centimeters.
5. Press Calculate. The main result shows the converted size, and the table below shows all four systems for that chart row with the step-by-step breakdown.

The US and UK systems share the same ancestor, the barleycorn, an old English unit equal to 1/3 inch. Both step a full size every 1/3 inch of foot length. But they start counting from different points, so a UK 8 and a US 8 are different lengths entirely. A men's US 9 lines up with a UK 8. That is why converting is never just subtracting a fixed number without knowing the right table.

The EU system took a different path. It is metric and counts in Paris points of 2/3 cm. Because it steps in whole numbers while US and UK step in halves, one EU size often covers two US half sizes. EU 41, for example, matches both US men's 8.5 and 9.

The CM system skips all of this. It is the Mondopoint base from ISO 9407, and it simply records foot length in centimeters. A 26.2 cm foot is 26.2 cm in every country, which makes it the most reliable number to compare across brands.

Conversions are only as good as the number you start from, so measure carefully. Measure in the evening, because feet swell during the day and an evening measurement matches how shoes fit when you wear them most. Stand on a sheet of paper with your heel against a wall, mark the tip of your longest toe, and measure from the wall to the mark in centimeters. Measure both feet and use the larger one, since most people have feet of slightly different sizes. Wear the socks you plan to wear with the shoes.

Enter the result in the CM option and the converter will find your nearest chart row. If you need the length in inches first, the length converter changes cm to inches and back.

Three mistakes cause most wrong conversions. First, mixing up men's and women's US sizes. For the same foot length, US women's sizes run about one size higher than men's. A 26.2 cm foot is a men's US 9 but a women's US 10. The UK column does not shift this way. It reads the same for men and women.

Second, forgetting that kids' size numbers repeat. The same US number appears once in toddler sizing and once in youth sizing at very different lengths. US kids' 4 is 11.6 cm in toddler sizing and 22.6 cm in youth sizing. When you convert a kids' size, the converter shows both rows so you can pick the right one.

Third, trusting EU sizes across brands. Published charts can disagree by a full EU size on the same foot, and brands cut shoes on different lasts. Use the conversion to get close, then check the brand's own chart.