👙 Bra Size
40AA Bra Size — UK, EU & French Conversion
A US 40AA bra in UK, European and French sizing, with its sister sizes. Not sure 40AA is right? Measure with the bra calculator first.
US 40AA = UK 40AA
EU 90AA · French 105AA
A US 40AA bra converts to UK 40AA, EU 90AA and French 105AA. The band number maps on a fixed scale, while cup letters shift between systems above D.
| Region | Size |
|---|---|
| US | 40AA |
| UK | 40AA |
| EU (Europe) | 90AA |
| FR / ES (France, Spain) | 105AA |
Sister sizes for 40AA
Same cup volume, different band — try these if the band feels tight or loose but the cup is right:
38ASister down
⚠️ US cup lettering above D varies by brand (DD vs E, DDD vs F). Match by the EU/UK equivalent when a brand's letters differ.
All bra sizes → · Bra calculator → · Converter →
What is a US 40AA bra in UK and EU sizing?
A US 40AA is a UK 40AA, EU 90AA and French 105AA.
What are the sister sizes of 40AA?
Same cup volume, different band: 38A.
ⓘ Affiliate links below. As an Amazon Associate we earn from qualifying purchases at no extra cost to you.
★ Top pick · Recommended on Amazon
Bras (Multipack)
Everyday bras once you know your size.
View on Amazon →Recommended on Amazon
Bra Band Extenders
Adjust the band a touch without changing the cup.
View on Amazon →