International Shoe Sizes

Why shoe sizes do not convert exactly

US, UK, European, Australian, and Japanese shoe labels grew from different systems. Some describe the last (the shaped form used to build a shoe), some are closely related to foot length, and some use different starting points for men, women, and children. A “size 9” therefore has no universal physical meaning until you name the region and sizing group.

Even within one system, brands allow different toe room, width, lining thickness, and intended fit. Running shoes may need extra space for swelling; formal shoes may use a narrower last; sandals can tolerate a different length relationship. This converter uses a practical comparison table rather than pretending that one formula predicts every manufacturer.

What the converter shows

Select adult men, adult women, or children first because US and Australian labels depend strongly on that category. Choose the system and size already printed on a shoe or size chart. The page finds the matching row and shows the closest US, UK, EU, Australian, and Japanese equivalents together with an approximate foot length in centimetres.

• US: separate adult men’s, adult women’s, and children’s sequences.
• UK: generally starts about one number below US men’s sizes, but the relationship varies for women and children.
• EU: commonly uses Paris points and does not normally print a separate men’s/women’s numbering scale.
• Australia: men’s sizes are commonly close to UK sizing; women’s retail labels are commonly close to US women’s sizing.
• Japan: commonly labels shoes by a centimetre-based length figure.

How to measure your foot

1. Put on the type of socks you expect to wear with the shoes.
2. Stand with full weight on a sheet of paper, heel lightly against a wall.
3. Mark the wall-side heel and the tip of the longest toe.
4. Measure that distance in centimetres, keeping the ruler straight.
5. Measure both feet and use the longer result.

The centimetre value in this table is a reference foot length, not the inside length of the finished shoe. Manufacturers add different allowances beyond the toes. If your measurement falls between rows, start with the larger nearby size and check the brand’s return and width guidance.

Worked examples

An adult men’s US 9 is approximately UK/AU 8, EU 42.5, and Japan 27 cm in this chart. An adult women’s US/AU 8 is approximately UK 5.5, EU 39.5, and Japan 25 cm. These are useful starting points when shopping internationally, but the product’s own chart should decide the final order.

Length is only one part of fit

Width systems vary just as much as length. Letters such as B, D, E, EE, or “wide” are not interchangeable across all brands or gendered ranges. High insteps, arch shape, heel width, and toe-box shape can make two shoes marked with the same size feel completely different. Orthotics also reduce available internal volume.

Children’s sizes need extra care

Children’s feet grow quickly, and size labels can switch from “C” (child) to “Y” (youth) in US charts. Avoid buying excessive growing room: too much length can make a child trip or grip with their toes. Re-measure regularly, and seek a trained fitter if gait, pain, or unusual wear is a concern.

Common mistakes

• Converting a US women’s size with a US men’s chart.
• Assuming Australian women’s and men’s scales follow the same regional counterpart.
• Using an old shoe’s printed size without noticing the brand already runs large or small.
• Measuring while seated, which can shorten and narrow the loaded foot.
• Confusing foot length with shoe insole or outsole length.

FAQs

Should I round up if I am between sizes?

Usually start with the larger size, especially for closed-toe athletic shoes, but follow the manufacturer’s fit notes and width options.

Are EU sizes the same for men and women?

The numbering system is generally shared, but lasts and width profiles can still differ between ranges.

Why is Japan shown in centimetres?

Japanese retail sizing commonly uses a length-based centimetre label, making it especially useful as a cross-check against a measured foot.

Can I use this for ski boots or specialist footwear?

Specialist footwear often uses Mondopoint, shell sizes, or discipline-specific fit rules. Use the maker’s fitting system rather than a general street-shoe chart.

Sources and limitations

The centimetre-first approach is consistent with the measurement principles behind ISO 9407 (Mondopoint). Regional equivalents are consolidated from common adult and children’s retail charts; no single international standard forces brands to use identical conversions. Results are educational estimates and should always be checked against the seller’s chart.