Shoe Size Converter

The shoe size converter translates shoe sizes between UK, US, EU, and other international sizing systems for men, women, and children. It is used by online shoppers buying from international retailers, travellers purchasing footwear abroad, and anyone trying to decode an unfamiliar sizing label. Select your size system and gender, then enter your size to find the equivalent in any other standard.

How to Use the Shoe Size Converter

1. Select your gender: men, women, or children.
2. Choose the sizing system your current size is in: UK, US, EU, or another standard.
3. Enter your shoe size number.
4. Click Convert to see the equivalent size in all major international systems at once.
5. If you are between sizes, the result will note this and suggest rounding up for comfort.

The Formula

Shoe sizes across systems relate to foot length. EU sizes are calculated as:

EU size = (Foot length in cm * 1.5) + 2, approximately

UK sizes use a different scale based on barleycorns (1/3 inch), starting at a different zero point:

UK size = (3 * Foot length in inches) - 25 (for men's sizing)

The relationship between UK and EU sizes is approximately:

EU size = UK size + 33 (for adults)

US men's sizes are typically 0.5 larger than UK men's sizes, while US women's sizes are approximately 1.5 larger than UK women's sizes. These are approximate conversion tables rather than exact mathematical formulas, because brands vary in their lasts (the foot-shaped moulds they use).

Real-World Example

A woman wears a UK size 6. Find her EU and US sizes.

1. EU size: UK 6 + 33 = EU 39
2. US Women's size: UK 6 + 1.5 = US 7.5 (some brands round to 8)

A UK women's size 6 corresponds to approximately EU 39 and US women's 7.5. When ordering from a US retailer, selecting size 7.5 or 8 is the right starting point, though sizing may vary by brand.

Why Shoe Sizing Is Inconsistent Between Brands

Unlike most measurement systems, shoe sizing is not fully standardised even within a single country's system. Different brands use different lasts, which affect the fit in width, arch height, and toe box shape, even if the nominal size is the same. Some brands run narrow, others wide. Luxury brands sometimes size differently to mass-market brands. Always check a brand's specific size chart and read customer reviews mentioning fit before purchasing footwear online, particularly from international retailers where returning items can be costly.

The table this converter works from

Shoe charts map one foot length onto every system at once. This converter applies the relationships set out in the formula section above, and the table below shows what each system reports for the same foot from an EU size of 38 to 45.

The foot length column is solved from the EU relation, EU = 1.5 x length + 2, rearranged to length = (EU - 2) / 1.5. The UK column applies the adult offset of 33. The US men's and women's columns apply the 0.5 and 1.5 differences stated above. The Japanese column rounds the foot length to the nearest half centimetre, which is how Japanese sizes are printed.

Every row follows from the same three rules, so you can rebuild the table for a size outside the range. Work the EU 41 row by hand: take 2 from 41 to get 39, divide by 1.5 to get 26.00 cm of foot length, then apply the offsets. UK is 41 - 33 = 8, US men's is 8 + 0.5 = 8.5, and US women's is 8 + 1.5 = 9.5.

Where does the 1.5 come from? The EU scale counts Paris points, and a Paris point is two thirds of a centimetre, so one centimetre is one and a half Paris points. That is the coefficient in the formula. The added constant of 2 absorbs the difference between the foot and the last, which is why the formula returns a size rather than a pure measurement.

Barleycorn arithmetic against the offset rule

The two halves of the formula section answer different questions, and running the same foot through both shows why shoe charts exist.

Start with the EU 41 row. The offset rule gives UK 8 for a 26.00 cm foot.

Now run 26.00 cm through the barleycorn formula. Convert to inches first: 26.00 / 2.54 = 10.2362 inches. Then 3 x 10.2362 - 25 = 30.7087 - 25 = 5.7087, so about a UK size 5.7.

The two methods sit more than two whole sizes apart for the same foot. Nothing has gone wrong in either calculation. The barleycorn scale counts thirds of an inch along the last, the mould a shoe is formed around, and a last runs longer than the foot it fits. The formula as written makes a single fixed subtraction of 25 to cover that gap, and one fixed allowance cannot hold across a size range that starts at infant sizes and ends at large adult ones. Repeat the comparison at EU 44, where the foot is 28.00 cm: the barleycorn formula gives 8.0709 and the offset rule gives UK 11.

The practical reading is that the two sides of this page do different jobs. Treat the barleycorn formula as the origin of the scale and the offset table as the working conversion. When a purchase depends on the exact number, choose a retailer that publishes the last length or the internal shoe length in centimetres, or use the brand's own chart, because that chart was built for the last that brand actually uses.

The Japanese size and the international standard

The Japanese size is the one figure on the table that needs no conversion at all. A Japanese size of 24.5 means a foot that measures 24.5 cm, because the system reports the measurement itself rather than a scaled number. That is why it is the easiest column to check against your own measurement.

The approach is also the international standard. ISO 9407:2019, Footwear sizing: Mondopoint system of sizing and marking, defines the Mondopoint system, in which a size is the foot length in millimetres with an optional width figure after it. A Mondopoint 265 is a 265 mm foot, or 26.5 cm. The standard sets the usual grading interval between whole sizes at 5 mm, with 7.5 mm used in some specialist footwear. Ski boots, military boots and performance skates use Mondopoint because a millimetre measurement travels between countries without a conversion table.

A Mondopoint figure converts to the Japanese column with a decimal point and nothing else. The EU column cannot be treated the same way, because it counts Paris points along the last rather than along the foot.

Measuring your own foot

Every conversion on this page starts from a foot length, so the measurement is worth getting right.

Measure late in the day rather than in the morning, because a foot spreads slightly under load and after walking. Stand on a sheet of paper with your heel against a wall, then mark the tip of the longest toe on each foot. Mark the longest toe, not the big toe, because the second toe is the longer one on plenty of feet. Measure heel to mark on both feet and use the larger figure, since feet are rarely the same size. Wear the socks you intend to wear with the shoe.

The converter expects a bare foot length with no allowance built in. If you measured with extra room in front of the toe, take that allowance off before you enter the number, or you will move a size up. Fitting guides commonly allow about a centimetre of clearance in front of the longest toe for a closed shoe, and that clearance belongs in the shoe rather than in the measurement you feed to a size chart.

Method and assumptions

The converter works from size tables rather than from a single continuous formula, and the assumptions are worth stating plainly.

The offsets are adult offsets. UK equals EU minus 33, US men's equals UK plus 0.5, and US women's equals UK plus 1.5. Children's sizes follow a different scale with its own reset, which the gender selector handles separately rather than by applying the adult offsets. Half sizes exist in the UK and US ranges but not in every EU range, so an exact half size may land between two available EU sizes. Foot length is solved from the EU relation, and the Japanese figure is that length rounded to the nearest half centimetre.

The table does not model width, arch height, toe box shape, or the last a particular brand uses. Two shoes labelled UK 8 can differ by half a size in fit for those reasons. Where a brand publishes its own chart, that chart outranks any general conversion, because it describes the last the shoe was built on.

Frequently Asked Questions

Are US men's and women's shoe sizes on the same scale? No. Men's and women's US sizes differ by 1.5 to 2 sizes for the same foot length. A women's US size 8 is approximately the same foot length as a men's US size 6.5. This is why some women wear men's shoes and need to size down.

Why do EU sizes not have half sizes in all brands? EU sizing is based on a continuous scale, but many European brands produce only whole sizes, while others include half sizes. The EU scale in theory allows half sizes, but production decisions vary by brand and market.

How do children's shoe sizes differ from adults'? Children's sizes in the UK and US start from size 0 for newborns and increase until reaching the adult scale, typically around UK/US size 13 children's, which then continues as UK/US size 1 adult. EU children's sizes run continuously from the smallest infant sizes upward without a separate adult-scale reset.

What is a Japanese shoe size? Japanese shoe sizes are expressed directly in centimetres of foot length, usually to one decimal place. A Japanese size 24.5 means the foot is 24.5 cm long, corresponding approximately to UK 6 or EU 38.5 in women's sizing.

Also try these free tools:

• Clothing Size Converter
• Ring Size Converter
• Unit Converter

Reference

ISO 9407:2019, Footwear sizing: Mondopoint system of sizing and marking, prepared by ISO technical committee TC 137. It replaces the first edition, ISO 9407:1991, and sets out the Mondopoint designation, the grading intervals and the marking format. Standard listing: https://webstore.ansi.org/standards/iso/iso94072019