Stop guessing whether US 10 = UK 9 or UK 8.5. Brand-by-brand sizing for Nike, Adidas, Lululemon, Gymshark, Hoka, On, Vuori, Alo and more — sneakers, leggings, sports bras and clothing.
The 5-second answer: Men's shoes — US is one full size larger than UK (US 10 = UK 9). Women's shoes — US is two sizes larger than UK (US 8 = UK 6). Clothing — Nike, Adidas, Gymshark and Lululemon use unified S/M/L sizing globally; Vuori, Alo Yoga and Beyond Yoga use US numerical sizing requiring conversion. Sports bras — different cup-systems entirely; convert with care.
| US Men's | UK Men's | EU | Foot length (cm) |
|---|---|---|---|
| 7 | 6 | 40 | 25.0 |
| 7.5 | 6.5 | 40.5 | 25.4 |
| 8 | 7 | 41 | 25.7 |
| 8.5 | 7.5 | 42 | 26.0 |
| 9 | 8 | 42.5 | 26.5 |
| 9.5 | 8.5 | 43 | 26.8 |
| 10 | 9 | 44 | 27.0 |
| 10.5 | 9.5 | 44.5 | 27.5 |
| 11 | 10 | 45 | 28.0 |
| 11.5 | 10.5 | 45.5 | 28.5 |
| 12 | 11 | 46 | 29.0 |
| 13 | 12 | 47.5 | 29.7 |
| US Women's | UK Women's | EU | Foot length (cm) |
|---|---|---|---|
| 5 | 3 | 35.5 | 22.0 |
| 5.5 | 3.5 | 36 | 22.4 |
| 6 | 4 | 36.5 | 22.7 |
| 6.5 | 4.5 | 37.5 | 23.1 |
| 7 | 5 | 38 | 23.5 |
| 7.5 | 5.5 | 38.5 | 23.8 |
| 8 | 6 | 39 | 24.1 |
| 8.5 | 6.5 | 40 | 24.6 |
| 9 | 7 | 40.5 | 25.0 |
| 9.5 | 7.5 | 41 | 25.4 |
| 10 | 8 | 42 | 25.7 |
| 11 | 9 | 43 | 26.5 |
Hoka's running shoes consistently run about half a size small. If you're a US 10 / UK 9 in Nike, you'll want a US 10.5 / UK 9.5 in Hoka. The Clifton, Bondi and Mach all behave this way.
On's running and lifestyle shoes (Cloud, Cloudmonster, Cloudnova) fit true to size. Order your normal Nike size.
Sambas fit true to size length-wise but are notably narrow. Wide-footed buyers should size up half. The pony-hair editions run noticeably tighter than the standard suede.
Nike's casual and training shoes (Air Max, Pegasus, Metcon) fit true to size. Air Force 1 runs slightly large — consider sizing down half. Dunk Low fits true to size.
New Balance shoes including the popular 990 series fit true to size and run notably wider than Nike or Adidas — comfortable for wide-footed buyers without sizing up.
| Brand | US Sizing System | UK Conversion | Notes |
|---|---|---|---|
| Nike | XS / S / M / L / XL | Same — unified globally | Athletic cut, true to size |
| Adidas | XS / S / M / L / XL | Same — unified globally | True to size, regular fit |
| Lululemon | 0, 2, 4, 6, 8, 10, 12 (women) · S/M/L (men) | UK 4 = Lulu 0, UK 6 = Lulu 2, UK 8 = Lulu 4, UK 10 = Lulu 6, UK 12 = Lulu 8 | True to size; women's sizes are roughly UK size minus 4 |
| Gymshark | XS / S / M / L / XL | Same — unified globally | Many products run small/tight by design |
| Vuori | XS / S / M / L / XL | Same labels but US-cut sizing | UK shoppers may want to size up; Vuori is cut on the slim side for US frames |
| Alo Yoga | XS / S / M / L | Same labels but US-cut | True to size; sculpting cut |
| Beyond Yoga | XS / S / M / L / XL | Runs slightly large vs UK equivalents | UK shoppers often size down |
Lululemon uses its own number system for women's clothing — confusing for both UK and US shoppers used to standard XS-S-M-L sizing. Here's how it maps:
| Lululemon size | UK size | US standard size | Bust (in) | Waist (in) |
|---|---|---|---|---|
| 0 | 4 | 0 | 31.5 | 24 |
| 2 | 6 | 2 | 33 | 25.5 |
| 4 | 8 | 4 | 34 | 26.5 |
| 6 | 10 | 6 | 35 | 27.5 |
| 8 | 12 | 8 | 36.5 | 29 |
| 10 | 14 | 10 | 38 | 30.5 |
| 12 | 16 | 12 | 40 | 32.5 |
| 14 | 18 | 14 | 42 | 34.5 |
Sports bras are the most painful conversion category. US bras use a different band/cup measurement system to UK. Quick reference:
| US bra size | UK bra size | EU |
|---|---|---|
| 32A | 32A | 70A |
| 32B | 32B | 70B |
| 32C | 32C | 70C |
| 32D | 32D | 70D |
| 32DD | 32DD/E | 70E |
| 34A | 34A | 75A |
| 34B | 34B | 75B |
| 34C | 34C | 75C |
| 34D | 34D | 75D |
| 36C | 36C | 80C |
| 36D | 36D | 80D |
Size 6. Lululemon women's sizing is roughly your UK dress size minus 4. UK 10 = Lulu 6, UK 8 = Lulu 4, UK 12 = Lulu 8.
UK 8 = US 10 in standard conversion. But Hoka runs small — so order US 10.5 (UK 8.5) for the best fit. Especially true for the Clifton.
For clothing — yes, exactly the same. Nike uses unified XS-S-M-L-XL across both markets. For shoes — no, US and UK shoe sizes are different (US 10 men's = UK 9). The shoe label itself shows both sizes; check the box.
Vuori is cut for typical US athletic frames — slightly more relaxed in the chest and shoulder, narrower at the waist. UK shoppers often find Vuori M fits like a UK S would. Size up if you prefer a more relaxed fit.
Look at the brand's country of origin. Lululemon is Canadian (uses N. American sizing); Gymshark is UK (uses UK-friendly unified sizing); Vuori, Alo, Beyond Yoga are US (use US sizing). Nike, Adidas, On are global (use unified S-M-L sizing for clothing, dual-labelled shoe boxes).
Use this guide alongside our trending picks for confident purchases on either Amazon store.