Bra sizing is widely misunderstood, so it’s not surprising that when a bra doesn’t fit as intended, most people assume that it must be the wrong size. It’s important to consider, however, that size is only part of the recipe for a proper bra fit; we need the right amount of space, but we also need that space to be in the right place. A well-fitting bra needs to match the shape of the wearer’s body. We’ll cover some of the specific elements of bra & body shape matching in other posts, but to get used to this idea, consider the balloon below. It contains a certain volume of air. For this demonstration, it’s going to represent a breast and its volume of breast tissue: a booballoon, if you will.

When it’s not being pressed or squeezed, the balloon is pretty close to round… a shape that most breasts tend not to be. There are many other ways to distribute that same volume, however. With a bit of coaxing, we can end up with all sorts of balloon shapes. We haven’t added or subtracted anything; we’ve just moved it around.

Breasts of the same “size” or volume can have very different shapes! Just like these balloon pictures, different people might have breasts that are more protruding or more compressed, wider or narrower, taller or shorter, more voluminous towards the bottom/top/outside/middle, or are rounder, pointier, teardrop-shaped, or shallow. All of these attributes are completely independent of size and exist on bodies across the spectrum of petite to busty.

Different bras will be a better or worse match for certain breast shapes because bras have shapes of their own. A bra with very shallow cups won’t work well for a body with extremely projected breasts. A wide breast base needs a bra with wide cups and a wide underwire (if it’s a wired style). Some bras are more adaptable than others, depending on what materials they’re made from. Cups with some ability to stretch and flex will work for a wider range of wearers because they have some ability to form to the body that dons them. However, if your preference is for dense foam padded “t-shirt” bras…

… you will likely need much more trial and error to find a close enough shape match to give you a comfortable and supportive fit. Stiff foam cups have a very specific shape manufactured into them, and if that doesn’t happen to be the way you’re built, it won’t work as intended in any size.

For more information on the shape elements of bra fitting, keep an eye on this blog, head over to the shape guide on Reddit’s A Bra That Fits forum, or drop in at Grail. Our fitting team can help you identify which bras have shapes most compatible with your needs.