B Cup Bras

A B cup means the difference between your bust and your underbust (band) measurement is about 2 inches. That difference determines your cup letter. To measure:

- Measure snugly under your bust for your band size.
- Measure around the fullest part of your bust for your cup size.
- Subtract the two numbers. A 2-inch difference typically corresponds to a B cup.

For a deeper breakdown of bra cup sizing, explore: A Complete Guide To Bra Cup: Comparing A, B, C, and D Cup Sizes

The number refers to your band size (ribcage measurement), while the letter B reflects the cup volume created by the 2-inch difference between bust and band.

So while all of these sizes share the same cup letter, the overall bra fit changes because the band size increases:

- 30B means smaller ribcage + B cup
- 32B, 34B, 36B, 38B, 40B mean progressively larger band sizes, each with the same B-cup difference

This is why a 30B and a 38B are both B cups, but the bras are designed for very different body proportions.

A B cup is generally considered in the average range. It offers moderate fullness, fuller than an A cup and less volume than a C cup. Keep in mind that the cup size is relative to body shape and band size, not a universal measurement. That’s why a B cup can look different on different frames, but is widely seen as a balanced, natural cup size.

B-cup sizes are versatile and work well with many bra designs, especially styles that offer natural shaping, smooth support, and everyday comfort. Some of the top picks include:

- Wireless Shaper Bra: great for daily wear with smoothing support and a natural look.
- Sweetheart Wireless Contour Bra: ideal for shaping and lift without padding, perfect under low or sweetheart necklines.
- Bralettes: a comfortable, lightweight option that provides gentle support and a relaxed feel.
- Strapless Bandeau Bra: perfect for off-shoulder, spaghetti straps, or special-occasion outfits.
- Posture Bra: offers additional back support while giving B cups natural lift and alignment.
- Wireless Lift T-Shirt Bra: seamless and smoothing under fitted tops, offering a clean silhouette without wires.

Each style complements the natural shape of B cups while balancing comfort, support, and versatility, making them great options for everyday outfits or special occasions.

For more context on how B cups compare to other sizes, you can explore: A Complete Guide To Bra Cup: Comparing A, B, C, and D Cup Sizes.