Shopping for clothes across borders turns a familiar size number into a small puzzle. A US 8 dress, a UK 12 dress and an EU 40 dress all point to the same garment, but only one of those numbers will be printed on the label you actually pick up in the store. Each country built its own ready-to-wear system years ago, tied the labels to different base measurements and step intervals, and never really synced them up afterwards. That is why the same body maps to three different numbers depending on where the brand is based, and why a free clothing size converter exists: it translates a single known size into the equivalent US, UK and EU sizes, plus an approximate S/M/L letter, so you can read across labels without doing the math in your head.
The converter works for both women's and men's apparel, but the two follow different conversion rules. Women's tops and dresses are numbered by dress size, where a UK size is the US size plus 4 and an EU size is the US size plus 32. Men's tops, jackets and suits are numbered by chest measurement in inches, where the US and UK share the same number and the EU size is exactly 10 higher. Because those two sets of rules do not line up, choosing the right category on the tool is the very first step before reading across the chart.
How to Use the Clothing Size Converter
The converter is built for the exact moment when you know one number and need the other two, plus a rough letter size to scan a rack or filter a product page. It updates in real time as you type and snaps to the nearest standard size if your number falls between two entries.
- Choose women's or men's at the top of the Clothing Size Converter, because a women's US 8 and a men's 40 chest are not the same garment and use different conversion logic.
- Select which system your known size is already in: US, UK or EU.
- Type the size number in the box, for example a US women's 8 or a men's 40 chest.
- Read the equivalent US, UK and EU sizes plus the approximate S/M/L letter size, all of which update in real time as you change the input.
- If your exact number is not a standard size, the tool snaps to the nearest entry and tells you so, so you know the result is an approximation and not a hidden guess.
Because the chart updates live, you can flip between women's and men's, or switch the source system from US to EU, without reloading. If you normally buy a US women's 8 and want to see what that is for a European storefront, switch the source system to US, type 8 and read the EU column. If you only know the EU number from a label printed in continental sizing, switch the source to EU and type that number instead.
Women's Clothing Conversion Rules
Women's apparel is the simpler of the two systems. Numeric sizes are dress sizes, and the three numeric systems line up predictably. For any women's top or dress, UK equals US plus 4 and EU equals US plus 32. A US 4 is a UK 8 and an EU 36; a US 8 is a UK 12 and an EU 40; a US 12 is a UK 16 and an EU 44. The EU column is the continental or French number printed on most labels from European high-street chains like Zara, Mango and H&M.;
Working the rules in reverse is just as easy. If you only know a UK number, subtract 4 to get the US size and add 28 to get the EU size. If you only know an EU number, subtract 32 to get the US size and subtract 28 to get the UK size. Those two directions cover the vast majority of women's cross-border shopping because most labels will tell you the country they were designed for before they tell you anything else.
Men's Clothing Conversion Rules
Men's apparel follows a different logic because tops, jackets and suits are sized by chest measurement in inches rather than by dress size. In practice, the US and UK use the same chest number, and the EU size is exactly 10 higher to convert from inches to the continental numbering. A US 40 chest is a UK 40 and an EU 50; a US 38 chest is a UK 38 and an EU 48; a US 44 chest is a UK 44 and an EU 54.
Working backwards is again straightforward. If you know the EU number on a European jacket, subtract 10 to get the US/UK chest size. If you know the UK size, it is already the US size because the two numbers are identical for men's tops. The shift of 10 reflects the original European decision to number jackets differently from the inch-based US and UK systems that standardized around full chest measurements.
Women's Clothing Size Chart
The reference chart below covers women's tops and dresses from US 0 through US 18. Each row lists the matching UK and EU numbers and the closest international letter size for that row. Letter sizes are the rough guide described in the section that follows, not fixed assignments.
| US | UK | EU | Letter (approx.) |
|---|---|---|---|
| 0 | 4 | 32 | XS |
| 2 | 6 | 34 | XS |
| 4 | 8 | 36 | S |
| 6 | 10 | 38 | S |
| 8 | 12 | 40 | M |
| 10 | 14 | 42 | M |
| 12 | 16 | 44 | L |
| 14 | 18 | 46 | L |
| 16 | 20 | 48 | XL |
| 18 | 22 | 50 | XL |
A US 4 lines up with a UK 8 and an EU 36; a US 8 lines up with a UK 12 and an EU 40; a US 12 lines up with a UK 16 and an EU 44. These are the three most useful anchors when shopping in women's apparel because they cover the small, medium and large bands that most stores default to.
Men's Clothing Size Chart
The reference chart below covers men's tops, jackets and suits from a 34 chest through a 48 chest. The US and UK columns are identical, the EU column adds 10 to that number, and the letter column is the closest international size.
| US | UK | EU | Letter (approx.) |
|---|---|---|---|
| 34 | 34 | 44 | S |
| 36 | 36 | 46 | S |
| 38 | 38 | 48 | M |
| 40 | 40 | 50 | M |
| 42 | 42 | 52 | L |
| 44 | 44 | 54 | L |
| 46 | 46 | 56 | XL |
| 48 | 48 | 58 | XL |
A US 38 chest is a UK 38 and an EU 48; a US 40 chest is a UK 40 and an EU 50; a US 44 chest is a UK 44 and an EU 54. Letter sizing in men's runs roughly S = 34-36, M = 38-40, L = 42-44 and XL = 46-48.
How Letter Sizes Map to Numbers
Letter sizes are the loosest part of any clothing conversion because they have no legal standard and drift between brands. As a rough guide, women's XS covers about US 0-2 (EU 32-34), S is US 4-6 (EU 36-38), M is US 8-10 (EU 40-42), L is US 12-14 (EU 44-46) and XL is US 16-18 (EU 48-50). S is roughly a 34-36 chest, M is 38-40, L is 42-44 and XL is 46-48. The converter prints the closest letter alongside the numeric result so you can scan a rack or a filter sidebar, but always confirm the underlying number against the brand's own chart because two brands in the same country can cut a medium differently.
The reason letter sizes drift so much is that brands use them as a marketing shorthand rather than a measurement. A "medium" at a fast-fashion chain often cuts smaller than a "medium" at a heritage label, and vanity sizing shifts numbers over time. Treat the letter column on the converter as a quick filter, not as the answer.
Why Conversion Charts Are a Starting Point
Each country standardized its ready-to-wear sizing independently, tying labels to different base measurements and step intervals, which is why the same body maps to different numbers across systems. That history also means two brands in the same country can cut a medium differently, and vanity sizing shifts the numbers over time as labels stretch to flatter customers. Fabric stretch, garment cut (slim versus relaxed) and how you personally like a piece to fit all change which numeric size is right for you. The converted size narrows the choice, but the brand's own chart, using your bust, waist and hips, plus trying the item on when possible, is the real confirmation. Treat the letter size as the loosest guide of all because it is the least standardized part of any conversion.
Two practical examples show why this matters. A European-cut wool blazer often runs narrower through the chest and shoulders than a more relaxed American-cut blazer at the same nominal size, so a converted EU 50 that fits perfectly in one brand may feel tight in another labeled EU 50. A stretchy cotton t-shirt at a US 8 will usually fit a wider range of bodies than a structured cotton shirt at the same US 8, because the fabric itself absorbs the difference between body and garment. These are exactly the cases where the converter narrows the choice and the brand chart, or a fitting room, closes the gap.
Measuring Yourself to Confirm the Converted Size
The most reliable cross-check after running a number through the converter is your own body measurements. For women's apparel, take your bust at the fullest point, your natural waist and your hips at the widest point, then compare each of those numbers to the brand's size chart for the converted size. For men's apparel, take your chest measurement under the armpits with the tape level across the back, your waist at the natural bend, and your neck if you are buying dress shirts. If your bust or chest sits between two chart sizes, sizing up usually gives a more comfortable fit in structured fabrics and a closer fit in stretch fabrics.
Keep a short note of these three numbers on your phone so you can pull them up the next time you shop across borders. The converter handles the country-to-country math; your measurements handle the brand-to-brand reality.
Quick Reference: Women's vs Men's Conversion Logic
The table below summarizes the difference between the two systems in a single glance, so you do not have to remember which rule applies where.
| Apparel type | Base measurement | UK vs US | EU vs US |
|---|---|---|---|
| Women's tops and dresses | Dress size | UK = US + 4 | EU = US + 32 |
| Men's tops, jackets and suits | Chest in inches | UK = US (same) | EU = US + 10 |
Once those two rows are clear, every other conversion is just arithmetic. The converter does the arithmetic for you, but knowing the underlying rules means you can sanity-check the result against any size chart you find online, including the brand-specific charts that always sit one click deeper than the generic conversion table.
Using the Converter on Resale Marketplaces
The same cross-border logic covered in this guide applies when you shop on resale marketplaces, where sellers often list garments using the sizing system of their own country rather than the buyer's. A European seller posting a high-street blazer may list it in EU sizing while a US buyer expects US numbers, and the converter sits in the middle to translate. For a full walkthrough of that workflow on one specific platform, see our guide on how to change clothing size on Vinted, which uses the same numeric systems and letter conventions covered here.