US to UK Women's Shoe Size Conversion
| US | UK |
|---|---|
| 5 | 3 |
| 5.5 | 3.5 |
| 6 | 4 |
| 6.5 | 4.5 |
| 7 | 5 |
| 7.5 | 5.5 |
| 8 | 6 |
| 8.5 | 6.5 |
| 9 | 7 |
| 9.5 | 7.5 |
| 10 | 8 |
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.
A different unit, not just a different number
UK women's shoe sizes are built on the English barleycorn system, where one full size equals a third of an inch of last length — a unit that predates the US sizing scale and has no shared origin with it. On the standard chart a US 8 lines up with a UK 6, a two-number gap that looks arbitrary until you realise the two countries were measuring shoes in different units long before either scale reached its modern numbering.
Because both the US and UK scales use half sizes, the conversion tends to be more consistent size-to-size than conversions into EU or Japanese systems, which is part of why 'US minus two' is a rule of thumb that gets repeated online. A US 6 or a US 12, at either tail of the run, is exactly where that rule starts to wobble — not every brand's UK line stocks a matching half size that far from the average foot.
Where the rule of thumb breaks
The 'minus two' shortcut assumes every brand's UK line is a perfect two-size shift of its US line, but that's a convention, not a law — some UK retailers selling US brands publish their own slightly different conversion, and a handful of British heritage shoemakers still cut lasts to older UK-only proportions that don't shift as cleanly. If a size matters, checking the brand's own chart catches this; assuming the shortcut always holds does not.
Fit beyond the number
UK last shapes vary by category more than by a single national tendency — British heritage leather shoes are often cut with a longer toe box than mainstream American styles, while UK fast-fashion brands frequently mirror US proportions closely since they're sourced from the same overseas factories. The size conversion gets you to the right ballpark; the specific brand's fit notes get you the rest of the way.
Children's and youth crossover sizing
One quirk worth flagging: UK sizing runs a single continuous scale from children's through adult sizes, so a small-footed adult woman occasionally finds herself shopping the UK 'grown-up' children's range (UK 1–5) rather than the women's range, which can throw off a straight US-to-UK lookup if the retailer's chart doesn't make the crossover explicit. If your converted UK size lands below 3, double-check whether the retailer's women's chart actually starts there or whether you need its junior/youth chart instead.
Frequently asked questions
Is 'US size minus two' always correct for UK sizing?
A UK retailer stocks the half sizes its typical customer actually buys, and demand thins out fast below a US 6 or above a US 12 — so the arithmetic itself doesn't fail at the tails, the matching UK half size just isn't always sitting on the shelf to convert into.
Why does UK sizing use different numbers from US at all?
UK sizing comes from the barleycorn system (a third of an inch per size), an older English measuring convention that was never aligned to the US scale — the two just count differently from the same rough foot-length range.
Do UK half sizes exist the same way US half sizes do?
Yes, most UK women's lines run half sizes the same way US lines do, which is why the US-to-UK conversion tends to be steadier than conversions into EU or Japanese sizing.
Why does my converted UK size sometimes show up under the kids' section?
UK sizing runs continuously from children's through adult ranges, so a small US women's size can convert to a UK number that some retailers still list on their youth chart rather than their women's one.