UK to US Clothing Size Conversion, Size by Size Table

If you have been sent here by a checkout page, the short answer is at the top of the table below. The longer answer is that the conversion works because of a piece of arithmetic that is almost a century old, and it stops working at exactly the point where we stopped being able to source anything solid — the top of the published table.

The table

UK	US	EU (DE)	FR	IT
4	0	30	32	36
6	2	32	34	38
8	4	34	36	40
10	6	36	38	42
12	8	38	40	44
14	10	40	42	46
16	12	42	44	48

So a UK 6 is a US 2, a UK 12 is a US 8, a UK 14 is a US 10 and a UK 16 is a US 12. Going the other way, add four.

Where the four comes from

This is not an arbitrary offset. Both systems were originally defined against bust circumference in inches, and they simply chose different zero points:

US size = bust − 28
UK size = bust − 24

Subtract one from the other and the four falls out. A 38-inch bust is a US 10 and a UK 14. A 40-inch bust is a US 12 and a UK 16. The gap is constant because it is baked into the definitions, not because anyone harmonised the two systems.

Knowing that also tells you what the conversion is not doing. It is not measuring you. It is translating between two labels that were both derived from the same bust measurement decades ago, by countries that picked different starting numbers.

Why the table stops being reliable

Three separate problems, in rising order of how much they will cost you.

1. Nothing enforces it. There is no mandatory clothing size or labelling standard in the US. A voluntary federal guide existed and “was eventually degraded to a voluntary standard until it was abolished altogether in 1983.” Since then the number on a label has been the brand’s decision.

2. Sizes drifted after the formulas were written. Vanity sizing “began in earnest in the 1980s,” and it did not move both systems at the same rate. The formulas above describe the historical scale, not necessarily the garment in your basket — which is how you end up with two size 10 dresses from different companies that “may have grossly different dimensions.”

3. Above the straight-size range there is no shared scale at all. US plus sizing does not continue the same ruler. ASTM D5585 covers the Misses figure type in 00–20; ASTM D6960 covers the Plus figure type in 14W–40W. Two tables for two figure types, not one continuous scale — that is what the titles say, and both standards are paywalled, so it is as much as we can tell you. Once your UK size is around 20 and up, the honest answer is that there is no label-to-label conversion to give you — there are only inch measurements.

The individual conversions people look up

The same table, read one row at a time, because that is usually how the question arrives.

UK 6 to US — a US 2.
UK 8 to US — a US 4.
UK 10 to US — a US 6.
UK 12 to US — a US 8. By the bust formulas, a UK 12 sits at a 36-inch bust and a US 8 at the same 36 inches, which is the offset working exactly as designed.
UK 14 to US — a US 10, at a 38-inch bust.
UK 16 to US — a US 12, at a 40-inch bust. Higher up, the two rulers stop continuing each other and start overlapping instead: on the Lands’ End chart a 14W has a larger waist (36½–37½) than a 16 (35–36½), with both listing the same 44½ hip. Those are not the same garment, and no offset converts between them.
US to UK — add four. A US 8 is a UK 12, a US 10 is a UK 14. Past the last row of the table above, the four is the formula rather than a published mapping.

Above a UK 20, stop converting. The US plus range is a different table for a different figure type, and adding four to a number that came off the other scale does not produce a size — it produces a guess with a number on it.

Shoe sizes do not use this offset

Worth saying because the two get mixed up constantly: the four-number clothing offset has nothing to do with shoes.

Shoe sizing runs on the barleycorn, “an old English unit that equates to 1⁄3 inch (8.5 mm),” and the UK and US scales differ by their own, much smaller amount. From foot length in inches, the approximate formulas are UK ≈ 3 × length − 23 and US women's ≈ 3 × length − 21. The constants differ by two, so US women’s shoe sizes run two numbers above UK — a UK 5 is a US 7, a UK 7 is a US 9.

Even that is softer than it looks — though note what the published caveat is actually about. It concerns the men’s offset: “most US manufacturers are using offsets greater than that standard; some offset by 1⁄2 barleycorn, others by 1 barleycorn.” We have not found an equivalent statement about the women’s scale, and we are not going to assume it is tighter. Measure the foot and convert from length.

What to use instead, in one minute

Convert the measurement, not the label.

Take three numbers. Bust at the fullest point, waist where you actually wear a waistband, hips at the fullest point. In inches and centimetres — UK and EU charts often lead with centimetres.
Open the size chart on the product page. Not a generic table. Not this one.
Find the row your largest measurement falls in. Too small at the hip is unwearable; slightly loose at the waist is usually fixable.
If you are between rows, size up and note by how much. The next order from that brand becomes a known quantity rather than another experiment.

That approach survives brands, countries and seasons, which is more than any conversion table manages.

A note on letters

If the page only offers S/M/L, the conversion table above will not help you and neither will anything else. Universal Standard maps L to 22–24; the Lands’ End women’s chart maps L to 14–16. Same letter, six to ten numbers apart, both published by the retailer. Letters are labels for position within one brand’s own range and cannot be converted at all.

The full explanation of why charts disagree — including the two ASTM tables and what a real retailer’s chart looks like when Misses and W sizes sit side by side — is in our clothing size chart women guide. The rest of the measurement walkthroughs are in size guides.

Sources

Clothing sizes — Wikipedia — the UK/US/EU/FR/IT comparison table, the bust formulas, the absence of a mandatory US standard, the 1983 abolition, vanity sizing
ASTM D5585-21 and ASTM D6960/D6960M-16(2023) — the Misses and Plus size ranges (titles only; the standards are paywalled)
Shoe size — Wikipedia — the barleycorn, the UK and US women’s formulas, and the variable manufacturer offsets
Universal Standard size finder and Lands’ End women’s trousers size chart — the two conflicting letter mappings

Frequently asked questions

What is a UK size 6 in US sizes?

A UK 6 is conventionally a US 2. The two systems run four numbers apart, so you subtract four going from UK to US. It is a convention rather than a standard, and it is only a starting point for a specific brand.

Is UK to US conversion always minus four?

The four-number offset holds across the conventional table, and it comes from the bust formulas: US size equals bust in inches minus 28, UK size equals bust minus 24. Individual brands are free to cut differently, and many do, so treat minus four as the default and the brand's own chart as the answer.

Do these conversions work for plus sizes?

Less reliably. The conventional table was built around the straight-size range, and US W sizing comes from a separate ASTM table drawn for a different figure type. Above roughly a UK 20 you should be comparing inch measurements rather than converting labels.