US to UK & UK to US Size Converter

Worked examples

A few common conversions, worked through:

• A US 6 dress is a UK 10. Add 4. If the UK brand's chart lists bust, waist and hip, check them too, as UK high-street sizing can run a little different from US brands.
• A US 10 jeans size is a UK 14. Jeans sold in W sizes don't change at all: a W30 is a W30 in both countries.
• A US women's 8 shoe is a UK 6. Subtract 2. Some brands say UK 5.5 or 6.5, so check the brand's chart.
• A US men's 10 shoe is usually a UK 9.5. Subtract half a size; a few brands subtract a full size, so check the chart.
• A US men's Medium shirt is a UK Medium. Men's letter sizes and chest sizes are the same.
• A US 34C bra is a UK 34C. Bands and cups match up to D, then the letters diverge.

The most common US to UK mistakes

1. Assuming a "10" is a 10. A UK 10 is a US 6, two clear sizes smaller than a US 10. This is the single most common mistake when shopping from UK sites.
2. Using the clothing rule for shoes. Clothing is US minus 4 to go from UK to US; shoes are UK plus 2 for women. Different rules, different directions.
3. Forgetting that cups diverge after D. A US DDD is a UK E; a US G is a UK F. Use the cup table, not the letter.
4. Ignoring the brand's own chart. The +4 rule is a convention, not a law. Some UK brands cut small, some large.

Bra sizes: US vs UK

Band sizes are the same in both countries. Cup letters match up to D, then go their separate ways:

So a US 36DDD is a UK 36E. For a full fitting, use the bust size calculator, and for the details, our US to UK bra size conversion.

Kids' clothing: US vs UK

US children's clothing is usually sold by numeric size (2T, 3T, 4, 5, 6) or letter size. UK children's clothing is almost always sold by age range, such as "4 to 5 years," often with a height.

These are typical; children vary a lot by height, so go by height rather than age. Our kids' clothing size chart and kids' clothing size calculator help.

Plus sizes and petite

The +4 rule continues into plus sizes: a US 16 is a UK 20, and a US 20 is a UK 24. Some UK brands label plus sizes as "curve" ranges. Petite works the same way in both countries, but UK petite usually means 5'3" and under, while US petite usually means 5'4" and under. See what petite sizing means.

Why the sizes don't match

US and UK clothing sizes grew up separately, with different starting points for the same body. Over decades, both sides also adjusted their sizes as average body shapes changed and brands competed on "smaller" labels, a habit known as vanity sizing. The result is a fixed offset that holds for most women's clothing, plus enough brand-to-brand variation that measurements are still the safest guide. For the full story, with every category in one place, see our guide to US to UK sizes for clothes.

Using the UK size with European sites

Many European retailers list UK sizes alongside EU sizes. If you know your US size, you can go via the UK: US 8 → UK 12 → EU 40. Or use the US to EU converter directly. Remember that Italian sizes run about 4 higher than EU sizes, so an EU 40 is an IT 44.

Shopping from UK retailers: practical tips

• Find the brand's size guide and compare your measurements in centimetres; UK charts usually list both.
• Check the returns policy for international orders, as return shipping can be expensive.
• Watch for "short", "regular" and "long" on UK trousers and jeans, which refer to leg length.
• Read reviews that mention "runs small" or "runs large."

If you sell to both US and UK shoppers, show both size systems on the product page so nobody has to convert in their head. Our guide on localising size charts by country explains how.