AA cup bra size
AA means a bust-to-band difference of less than 1 in on US, UK, EU, FR/BE and AU/NZ tags.
In US sizing a AA cup is a difference of 0 in (0 cm) between bust and band.
AA at 0 in, system by system
A cup letter stands for a difference between bust and band. The same letter sits at a different difference in some systems.
| System | Difference (in) | Difference (cm) | Written as |
|---|---|---|---|
| US | 0 | 0 | AA |
| UK | 0 | 0 | AA |
| EU | 0 | 0 | AA |
| FR/BE | 0 | 0 | AA |
| AU/NZ | 0 | 0 | AA |
| JP | Not used | Not used | Not used |
| EU method (cm) | Measured in cm | 10 to 12 cm | AA |
Where sources disagree about AA
The sources used here agree on this letter. They differ on other points, which the methodology page lists.
For AA, US, UK, EU, FR/BE and AU/NZ each show 0 (less than 1) in. The EU method gives AA a bust-minus-band span of 10 cm up to but not including 12 cm, the stated centimetre distinction.
AA starts the sequence in US, UK, EU, FR/BE and AU/NZ, with A after it. JP has no AA letter in its chart; JP letters vary by brand, and the chart lists them only for part of the range.
For AA under the EU method, the range is 10 cm up to but not including 12 cm. This gives AA its own centimetre expression alongside the inch figure.
On bands 32 and 34, AA is listed at bust ranges of 31.5 to 32.5 in (80 to 82.6 cm) and 33.5 to 34.5 in (85.1 to 87.6 cm).
On bands 36 and 38, AA is listed at 35.5 to 36.5 in (90.2 to 92.7 cm) and 37.5 to 38.5 in (95.3 to 97.8 cm). AA has no preceding letter in these sequences, and A follows. For AA, published charts differ only on JP: one chart has no AA, while charts that print AA show none before it and A after. The listed inch difference is the same in US, UK, EU, FR/BE and AU/NZ.
Questions
What does a AA cup mean?
A AA cup is a difference of 0 in (0 cm) between bust and band in US sizing. The letter names the size of that difference.
Which difference is a AA cup in each system?
US 0 in, UK 0 in, EU 0 in, FR/BE 0 in, AU/NZ 0 in and JP does not use it.
Do all systems write a AA cup the same way?
Not everywhere. In US sizing it is 0 in, and JP (not used) differ.