The full ladder
Cup letter by inch difference
| Difference | US | UK | EU / France |
|---|
Below a D cup, all three columns agree. Above it, naming conventions diverge — the same body can be labelled differently depending on which chart the brand used.
Why the split happens
Where and why letters disagree
Universal agreement
AA through D describe the same inch difference in essentially every English-language and European system.
No shared standard
Once past a D cup, there was never one global agreement, so US, UK and EU systems each built their own extension of the scale.
DD vs. single letters
The UK doubles letters (DD, FF), the US sometimes uses DDD, and EU/French systems often prefer moving to the next single letter instead.
Charts are guidelines, not law
Individual brands sometimes deviate from all three columns, which is exactly why trying a size in person still matters.
Questions
Cup letter FAQs
US and UK letters match through a D cup. From there, a US DD becomes a UK E, and the naming gap tends to widen by roughly one letter further up.
European conventions historically avoided doubled letters, so an EU chart's "E" commonly lines up with a UK "DD" rather than repeating the letter.
Yes — the scale keeps climbing (J, JJ, K and beyond in some systems), though fewer mainstream brands stock these ranges compared to specialist retailers.
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