Why clothing sizes disagree and shoe sizes do not
A shoe size is a name for a foot length. A ring size is a circumference in millimetres. A dress size is a name for nothing in particular. Clothing is the one category on this site where the conversion between countries is exact and the conversion between shops is not, and it is worth understanding why before you trust any chart, including this one.
The offsets are fixed. The bodies are not.
Converting a women's clothing size between countries is arithmetic. Across the standard range the UK number runs 4 above the US number, without exception. The EU number runs 32 to 32 above the US number, and Italy runs a further four above the EU. Those relationships hold up and down the chart, which is why a conversion table for clothing looks reassuringly tidy.
The tidiness is misleading. What the arithmetic converts is a label into another label. It says nothing about which body either label was cut for, and that is the part that varies, between brands, between product lines within one brand, and across a decade within one product line.
One body, five labels
The table below is built from the bust measurement outwards rather than from any one country's scale, which is the argument of this page in table form. Read a row and you are looking at one body wearing five different numbers.
| Bust (cm) | Letter | US | UK | EU | Italy | France |
|---|---|---|---|---|---|---|
| 78 to 81 | XS | 0 | 4 | 32 | 36 | 32 |
| 82 to 85 | XS | 2 | 6 | 34 | 38 | 34 |
| 86 to 89 | S | 4 | 8 | 36 | 40 | 36 |
| 90 to 93 | S | 6 | 10 | 38 | 42 | 38 |
| 94 to 97 | M | 8 | 12 | 40 | 44 | 40 |
| 98 to 101 | M | 10 | 14 | 42 | 46 | 42 |
| 102 to 105 | L | 12 | 16 | 44 | 48 | 44 |
| 106 to 110 | L | 14 | 18 | 46 | 50 | 46 |
| 111 to 116 | XL | 16 | 20 | 48 | 52 | 48 |
| 117 to 122 | XL | 18 | 22 | 50 | 54 | 50 |
| 123 to 128 | XXL | 20 | 24 | 52 | 56 | 52 |
Notice that the letter column repeats: two consecutive numeric sizes share one letter nearly the whole way down. That is the letter system telling you honestly how much precision it has. S, M and L cover a range roughly twice as wide as a numeric size, so a garment sold only in letters is a garment that will fit a wider variety of people slightly less well, which is often exactly the intention.
Why no standard fixes this
There is a European standard, EN 13402, which sets out how to designate a clothing size from body dimensions in centimetres, together with the pictogram labelling that goes with it. There is ISO 8559-1, which defines where on the body each measurement is taken. Between them they describe how to do this properly.
Neither is binding. No law requires a brand to designate sizes that way, and most do not. Compare that with footwear, where ISO 9407 defines the Mondopoint system in millimetres of foot length and a great deal of manufacturing follows it because the product physically has to fit a measured foot, or with rings, where ISO 8653 makes the EU size literally the inner circumference. Clothing has the standards and lacks the adoption.
What to do about it
Convert countries using the table above, and convert brands using a tape measure. Concretely:
- Measure bust, waist and hip once, in centimetres, and write them down. They change slowly and they are the only numbers in this whole area that are about you rather than about a label.
- Look for the brand's body-measurement table, not their size chart. A brand publishing centimetres can be compared with any other brand publishing centimetres. A brand publishing only S, M and L has told you they would rather you did not.
- When two measurements point at different sizes, size to the largest one for structured garments and to the smallest for stretch. A jacket cannot be let out; a jersey top can stretch.
- Treat any conversion between two brands as an estimate, including one from this site. Between countries the conversion is arithmetic; between brands it is a guess with a good starting point.
For the full tables see the clothing size chart, for measuring see how to measure clothing size, and for how this site derives every column see the methodology.
Common questions
Why does the same body fit two different sizes in two shops?
Because no law or standard fixes what a clothing size means. EN 13402 describes how to designate a size from body measurements, but nothing requires a brand to follow it, and most set their own fit. Two shops labelling the same bust differently are both within their rights.
Is the offset between US and UK sizes fixed?
The numeric offset is: UK numbering runs four above US numbering across the standard women's range, so a US 8 is a UK 12. What is not fixed is which body either number describes, which is why the offset converts labels reliably and fit unreliably.
What is vanity sizing?
The slow drift of a size label onto a larger body over time, so a garment labelled with a smaller number flatters the buyer. It moves at different speeds in different markets and price points, which is one reason a conversion between two brands ages worse than a conversion between two countries.
What should I go by instead?
The body measurement. Bust, waist and hip in centimetres are facts about you, not about a label, and any brand publishing a body-measurement table can be compared with any other. If a brand publishes only letters, that is information about the brand.
Last reviewed and updated on August 5, 2026. Conversion tables are checked against published international sizing standards.