Quick answer: To convert a UK shoe size to a US size, add 1 for men’s shoes and add 2 for women’s shoes. A men’s UK 8 is a US 9, and a women’s UK 5 is a US 7. Some sportswear brands use a gap of 2.5 for women, so always check the brand’s own chart before ordering.
Buying trainers from an American website, or reading a US size on a box, is easy once you know the offsets. The charts below cover adult women’s and men’s sizes with EU equivalents and an approximate foot length, so you can cross-check against a tape measure. For more sizing guides, see the body and clothing measurement hub.
How do you convert UK shoe sizes to US sizes?
Add one size for men and two sizes for women. Both countries count adult shoe sizes in steps of one barleycorn, an old English unit of one third of an inch (about 8.5 mm), so the scales run in parallel. They simply start counting from different points, which is why the gap stays the same all the way up the range.
- Men: US size = UK size + 1. A UK 10 is a US 11.
- Women: US size = UK size + 2. A UK 6 is a US 8.
- Going the other way: subtract 1 (men) or 2 (women) from the US size to get the UK size.
Half sizes follow the same rule, so a women’s UK 4.5 becomes a US 6.5.
UK to US women’s shoe size chart
A women’s UK 5 is a US 7 and roughly an EU 38. The EU column uses the standard Paris-point calculation rounded to the nearest half size. The foot length column is a guide to the length of foot each size suits, not the length of the shoe itself.
| UK size | US women’s | EU (approx.) | Foot length (approx.) |
|---|---|---|---|
| 2 | 4 | 34.5 | 21.2 cm (8.3 in) |
| 2.5 | 4.5 | 35 | 21.6 cm (8.5 in) |
| 3 | 5 | 35.5 | 22.0 cm (8.7 in) |
| 3.5 | 5.5 | 36 | 22.4 cm (8.8 in) |
| 4 | 6 | 37 | 22.9 cm (9.0 in) |
| 4.5 | 6.5 | 37.5 | 23.3 cm (9.2 in) |
| 5 | 7 | 38 | 23.7 cm (9.3 in) |
| 5.5 | 7.5 | 38.5 | 24.1 cm (9.5 in) |
| 6 | 8 | 39.5 | 24.6 cm (9.7 in) |
| 6.5 | 8.5 | 40 | 25.0 cm (9.8 in) |
| 7 | 9 | 40.5 | 25.4 cm (10.0 in) |
| 7.5 | 9.5 | 41.5 | 25.8 cm (10.2 in) |
| 8 | 10 | 42 | 26.2 cm (10.3 in) |
| 8.5 | 10.5 | 42.5 | 26.7 cm (10.5 in) |
| 9 | 11 | 43 | 27.1 cm (10.7 in) |
UK to US men’s shoe size chart
A men’s UK 9 is a US 10 and roughly an EU 43.
| UK size | US men’s | EU (approx.) | Foot length (approx.) |
|---|---|---|---|
| 5 | 6 | 38 | 23.7 cm (9.3 in) |
| 5.5 | 6.5 | 38.5 | 24.1 cm (9.5 in) |
| 6 | 7 | 39.5 | 24.6 cm (9.7 in) |
| 6.5 | 7.5 | 40 | 25.0 cm (9.8 in) |
| 7 | 8 | 40.5 | 25.4 cm (10.0 in) |
| 7.5 | 8.5 | 41.5 | 25.8 cm (10.2 in) |
| 8 | 9 | 42 | 26.2 cm (10.3 in) |
| 8.5 | 9.5 | 42.5 | 26.7 cm (10.5 in) |
| 9 | 10 | 43 | 27.1 cm (10.7 in) |
| 9.5 | 10.5 | 44 | 27.5 cm (10.8 in) |
| 10 | 11 | 44.5 | 27.9 cm (11.0 in) |
| 10.5 | 11.5 | 45 | 28.4 cm (11.2 in) |
| 11 | 12 | 45.5 | 28.8 cm (11.3 in) |
| 11.5 | 12.5 | 46.5 | 29.2 cm (11.5 in) |
| 12 | 13 | 47 | 29.6 cm (11.7 in) |
| 12.5 | 13.5 | 47.5 | 30.1 cm (11.8 in) |
| 13 | 14 | 48.5 | 30.5 cm (12.0 in) |
The approximate foot lengths line up closely with the foot lengths Clarks publishes for its UK sizes (for example around 221 mm for a women’s UK 3 and 272 mm for a UK 9). If your measured foot falls between two rows, the larger size is usually the safer choice for walking or running shoes.
Why do some brands use a different conversion?
There is no single legal standard that every brand follows, so the offset can shift by half a size. Nike’s UK size chart, for instance, lists a women’s UK 5 as a US 7.5, a gap of 2.5 rather than 2.
Lasts (the moulds shoes are built around) also differ between factories. The practical approach is:
- Measure your foot. Stand on paper with your heel against a wall and mark the tip of your longest toe; the guide to measuring your foot size shows the method.
- Find the brand’s own chart. Look for one that lists foot length in cm or mm, not just size numbers.
- Match the length, then the label. Use the foot length to pick the row, then read off the US size in that brand’s column.
How do children’s sizes convert from UK to US?
Children’s sizes usually convert at about half a size to one size up, but brand charts vary more than for adults. The UK children’s scale runs from 0 to 13.5 before restarting at adult size 1. Because growing feet need room, measuring is more reliable than converting a number; the guide on measuring children’s feet explains how much growing space to allow.
What about width fittings?
Widths are labelled differently on each side of the Atlantic, so length conversion alone may not be enough. UK brands such as Clarks use letters like D (women’s standard) and G (men’s standard), with E, EE or H for wider fits. US brands typically use B for a women’s standard width and D for a men’s standard width, with 2E and 4E for wider feet.
Common mistakes when converting shoe sizes
- Using the men’s offset for women’s shoes. A unisex trainer is often labelled in US men’s sizes, so a woman who wears UK 5 would look for US men’s 6, not 7.
- Assuming EU sizes convert neatly. One EU size is two thirds of a centimetre; one UK size is a third of an inch (about 0.85 cm), so the two scales never line up exactly.
- Measuring in the morning. Feet tend to swell during the day, so measure later on and wear the socks you plan to use.
If you need to convert a foot length between centimetres and inches, the cm to inches converter gives exact figures, and the site’s shoe and ring size charts cover further international sizes.
Frequently asked questions
Is a UK 7 a US 8 or a US 9?
A men’s UK 7 is a US 8 and a women’s UK 7 is a US 9. The difference comes from the US using separate men’s and women’s scales while the UK uses one.
What is a US women’s 8 in UK sizes?
A US women’s 8 is usually a UK 6. With brands that use a 2.5-size gap, such as Nike, it is closer to a UK 5.5.
Are US shoe sizes bigger than UK sizes?
The shoes are not bigger, but the numbers are. The same physical shoe carries a US number one higher (men) or two higher (women) than its UK number.
How big is one shoe size?
One full UK or US size is one barleycorn, which is a third of an inch or about 8.5 mm. A half size is about 4.2 mm. One EU size is two thirds of a centimetre, about 6.7 mm.
What US size is a UK 10 for men?
A men’s UK 10 is a US 11 and roughly an EU 44.5. It suits a foot of about 27.9 cm (11 in).
Sources
- Clarks: Finding your perfect fit (UK sizes, foot lengths and width fittings)
- Nike UK: women’s footwear size chart
- ISO 9407:2019 Shoe sizes: Mondopoint system of sizing and marking