Ordering From a European or British Shop? Here's What Your Size Actually Is
A "US 8" is not an EU 8, and a "UK 10" is not a US 10 — the numbers on the label come from three different measuring systems, not the same scale shifted around. Here's how the conversion actually works, with worked examples for clothing, shoes, kids, and bras.
Short answer: Each country's system was built around a different reference point — the US uses small consumer-facing numbers, the EU derives sizes from a body-measurement or height standard, and the UK uses its own small-number scale offset from the US. None of the three scales start at the same place, so converting is not "subtract two" — it follows a different offset for every category.
This is the exact problem ToolPico's Clothing Size Converter is built to solve. Instead of memorizing offsets, you pick a category — women's, men's, shoes, kids, or bra — enter the size or measurement you already know, and every other system (including extended references for Japan, Korea, Australia, France, and Italy) updates instantly. It also works in the other direction: enter a bust/waist/hip, chest, or foot-length measurement in inches or centimeters, and the tool finds your closest match without you needing to know your size in any system first.
Rule of thumb: Convert first with a reference chart, then always cross-check the retailer's own centimeter or inch measurements on the product page — brand cut varies enough that the converted "equivalent" size is a starting point, not a guarantee.
Women's and men's clothing: the actual offsets
Short answer: For women's clothing, EU size ≈ US size + 32, and UK size ≈ US size + 4. Men's clothing is read differently — suits and jackets are sized by chest circumference in inches (US/UK) or centimeters (EU), and shirts are sized separately by neck/collar circumference.
For example, a US women's size 6 converts to roughly an EU 38 and a UK 10 — using the rule above (6 + 32 = 38, 6 + 4 = 10). A US 8 lands at EU 40 / UK 12, and so on up the scale. These offsets hold reasonably well through the mid-range of sizing, though brand cut and category (dresses vs. denim vs. outerwear) introduce their own variance on top.
Example — women's clothing (illustrative; check brand chart for exact fit)
US
EU
UK
Letter
4
36
8
S
6
38
10
S/M
8
40
12
L
10
42
14
L/XL
Men's sizing works on a different logic entirely: a dress shirt collar of 15.5 inches converts to roughly 39-40 cm in the EU system, and roughly corresponds to a letter size M. Suit and jacket sizing is set by chest circumference, tracked separately from collar size — which is why a "size 40" suit jacket and a "15.5 collar" dress shirt are two unrelated measurements on the same body.
Example scenario: say a shopper knows they wear a US women's 8 and want to order a dress from a French retailer that only lists EU sizes. Converting gives EU 40 (also roughly a French 40, since France uses the same numbering as the EU standard) — but the shopper should still check the brand's own bust/waist/hip cm chart before ordering, since fast-fashion cuts in particular vary from this reference.
Shoes: US, EU, UK, and foot length
Short answer: Shoe sizing is ultimately based on foot length, measured in the Mondopoint/EU (Paris-point) system. A 25 cm foot is roughly an EU 39-40; that's about a US men's 7-7.5 or a US women's 8.5-9, since women's US shoe sizes run about 1.5 sizes larger than men's for the same physical foot length.
This is the most measurement-driven category of the bunch, and the converter reflects that: it has a dedicated foot-length field (in cm or inches) with a width selector (narrow/normal/wide), plus a men's/women's/kids' toggle so the same physical length maps correctly to the right gendered scale.
Example — foot length to shoe size (illustrative reference)
Foot length
EU
US men's
US women's
24 cm
38
5.5
7
25 cm
39-40
7
8.5
26 cm
41
8
9.5
27 cm
43
9.5
11
Example scenario: a shopper measures their foot at 25 cm heel-to-toe in the evening (feet swell during the day, so an evening measurement is more reliable) and wants a pair of unisex sneakers sold only in men's US sizing. Converting gives roughly a men's US 7 — and if that shopper normally buys a women's US 8.5, that also checks out, since men's size ≈ women's size − 1.5.
Kids' sizes and bra sizing
Short answer: Kids' clothing should be chosen by height, not age — EU kids' sizes are literally a height label in centimeters (a size 104 is meant for a child about 98-104 cm tall). Bra sizing combines a band measurement (underbust) and a cup letter derived from the bust-minus-band difference, and the band number itself is given in inches (US/UK) or centimeters (EU).
Because children of the same age can vary in height by 10-15 cm, an age label like "3-4 years" is a much rougher guide than an actual height measurement. The converter's kids mode reflects this by leading with a height (cm or in) input rather than an age dropdown alone.
For bra sizing, the tool takes a band and bust measurement (in cm or in) and calculates the size across US, UK, and EU automatically — or, going the other direction, lets you pick a known US/UK band-and-cup combination to see the EU equivalent plus a "sister size" suggestion (one band size up or down paired with one cup size down or up, which often fits similarly).
Sister sizingA band-and-cup adjustment where moving one band size in one direction and one cup size in the other direction (e.g., 34C → 36B) often produces a very similar overall fit — useful when a specific size is out of stock.
Example scenario (illustrative): a parent measures a child at 102 cm tall. That lands close to a EU size 104, roughly a US 4T, and roughly a UK age label of 3-4 years — again, treat the age label as the least reliable of the three.
Skip the manual math — convert any of these categories instantly, including a body/foot-measurement lookup.
In women's clothing, a US size 8 is equivalent to an EU 40, a UK 12, and roughly a letter size L. The general rule for women's sizing is EU = US + 32 and UK = US + 4. Men's shirt and suit sizing is read differently (by chest or collar measurement in inches), and exact fit still varies about half a size by brand.
What US shoe size is an EU 40?
An EU 40 shoe is roughly a US men's 7, a UK 6.5, and about a 25.5 cm foot length. In women's shoes, an EU 40 is roughly a US women's 8.5 and a UK 6.5. For the same physical foot length, the women's US size runs about 1.5 sizes larger than the men's US size.
What US size and age is a kids' size 104?
A EU/kids size 104 corresponds to a child roughly 98-104 cm tall, which is about a US size 4T and a UK age 3-4 label — typically around 4 years old. Kids' sizing should be chosen by height rather than age, since children of the same age can vary in height by 10-15 cm.
What is a US 34B bra in UK and EU sizing?
A US 34B bra is the same as a UK 34B, and roughly an EU 75B. The band number (34) reflects a ribcage/underbust measurement of about 30-32 inches (roughly 78-82 cm in the EU system, where band numbers are given in centimeters instead of inches). Cup letters diverge between systems after D: a UK/US DD is roughly an EU E.
Is a size chart the same for every brand?
No. These charts are a standard reference, but every brand cuts to its own pattern. For example, Zara and Mango tend to run small, Nike shoes often run about half a size small, and brands like Old Navy or Uniqlo tend to run closer to true-to-size or relaxed. Whenever possible, compare the converted size against the brand's own measurements before buying.
A note on the numbers: The examples and small tables above are a standard international reference (comparable to Mondopoint/ISO 9407 for shoes and the EN 13402 height system for kids), included for illustration. They are not a substitute for a specific brand's own measurements, and this article is general shopping guidance only — not a guarantee of fit.