B cup bras: the most common size

Approximately fifteen centimetres separate the bust measurement from the back measurement on a bra cup B. This is the most commonly produced depth in the French market, which has a direct practical consequence: this is the size where the choice of shapes, materials, and colours is the widest. You can find a bra cup B from 80 to 100, which is not the case for any larger depths.

The cup B and sister sizes

This depth is also where sister sizes are most often found. A 90B and a 85C offer the same volume of cup, the only difference being the band size. If your regular bra cup B feels a bit loose, try the size down in the band with a cup C: the band will fit better and the cup will be the same. This is the most useful adjustment to know for this size.

Which shapes to choose in cup B

All shapes work, which makes the choice more open than for other depths. Balconette and half-cup styles provide lift without padding. Smooth cups remain invisible under a t-shirt. The triangle and bralette styles offer comfort for everyday wear. The push-up style accentuates the cleavage. The only useful advice is therefore to choose based on the use and the garment worn over it, not based on an assumed size constraint.