UK to US Women's Shoe Size Conversion
| UK | US |
|---|---|
| 3 | 5 |
| 3.5 | 5.5 |
| 4 | 6 |
| 4.5 | 6.5 |
| 5 | 7 |
| 5.5 | 7.5 |
| 6 | 8 |
| 6.5 | 8.5 |
| 7 | 9 |
| 7.5 | 9.5 |
| 8 | 10 |
Sizing conventions vary by brand and by cut — this table shows the standard published conversion. Always check the garment's own size chart when one is available. See how these tables are compiled.
Reading a UK size onto a US shoe wall
UK women's shoe sizes are counted in barleycorns — a third of an inch per whole size — a unit with no connection to the US sizing scale, which is why a UK 6 becomes a US 8 on the standard chart rather than sitting close to the original number. It's a genuine unit translation, not a rebrand of the same scale.
Both scales use half sizes and shift in step over most of the women's range, which is why 'UK plus two' works as a shortcut more often than the equivalent EU or Japanese conversions do — the two sections below cover the specific situations (a UK 2–3, or a heritage-made shoe) where that shortcut needs a second check.
Heritage British lasts are the exception
If the shoe in question is from a long-established British shoemaker rather than a mainstream fast-fashion brand, be more cautious with the shortcut — some heritage UK lasts are cut to older, narrower proportions that don't map onto typical American last shapes as cleanly as the size-number conversion suggests. A mainstream UK high-street brand converts far more predictably than a traditional English shoemaker's own house last.
What to verify before you buy
For anything you can't try on, convert your UK size to an actual foot length in inches or centimetres and check it against the US retailer's own chart. Retailers who sell into both the UK and US markets typically publish that length figure precisely because the size-number shortcut, while usually close, isn't precise enough on its own for a purchase you're committing to sight unseen.
Watch the low end of the women's range
UK sizing runs continuously from children's into adult sizes, so a UK 3 or smaller sits at the boundary where some retailers' 'women's' chart stops and their youth chart begins. If you're converting a small UK size and the US number that comes back looks unusually large or small compared to what you'd expect, check whether you were actually reading a youth-range UK chart rather than the adult women's one — an easy mix-up that a straight number conversion won't catch on its own.
What a UK shopper should check before a first US order
US shoe retailers more consistently publish a foot-length-in-inches column alongside the size number than many UK sites do, which is worth using directly if your foot sits near a half-size boundary, since it removes a layer of rounding that a straight UK-to-US size lookup can’t avoid.
Frequently asked questions
Is 'UK size plus two' reliable for US sizing?
Two things break it, neither one about the arithmetic: a genuinely small UK size (2–3) that some US retailers only stock on a youth chart, and a traditional English shoemaker's own house last, which was never built to the mainstream high-street proportions the shortcut assumes in the first place.
Why is UK sizing numbered so differently from US?
UK sizes are counted in barleycorns, a third-of-an-inch unit from an older English shoemaking tradition, unrelated to how the US scale was built — the numbers were never meant to align.
Do British heritage shoe brands convert the same way as high-street brands?
Not always. Some traditional English shoemakers cut lasts to older house proportions that sit narrower than typical American lasts, so the standard size conversion is a rougher guide there than it is for mainstream UK brands.
Why would my small UK size convert oddly compared to friends' sizes?
UK adult and children's sizing share one continuous scale, so a very small UK women's size sits close to the youth range boundary — check you're reading the women's chart, not a youth chart, before converting.