Bustyresources Wiki

There are many parts of a bra.[1]

Bra anatomy, or the parts of a bra, may vary from bra to bra, yet a few basic structures remain common to most all bras. By varying these structures, more or less support for the breasts can be provided. Thus, understanding the anatomy of a bra can help with adjusting the bra to create the perfect fit.

Bra anatomy of modern bras can be explained thoroughly. There are many parts of a bra,[1][2][3][4] all of which together have different effects on a bra's overall fit and comfort.

A bra is made from approximately 12 x pieces of fabric, 2 x foam cups, 2 x underwires, 2 x sliders, 2 x rings and 1 set of hook and eye closures. It can take 6 months for a bra to be developed from design stage to pre-production (sometimes more), with up to 50 highly skilled people working on countless prototypes and with components coming from perhaps as many as 6 different countries.[1]

Parts include the band, gore, side panel, cup, apex, neckline, underwire, strap, ring, slider, strap join, and closure.



The regions of the bra that support the most weight are colored in dark red; the least supportive regions are blue. The bra band should provide the most support.[5]

One of the most important parts of a bra, the bra band, is the part that runs around the rib cage of the wearer. The cups are attached to the front of the bra band, the straps to the back, and in the center of the bra band is where the hook and eye closures are typically located (either the front or the back). The center gore is actually a part of the band. The strap join in the back is a key feature to look for in a supportive bra; the strap should continue along the bra band's edge.

The bra band contributes the most to a bra's fit. In a well-designed bra, most of the weight of the breast is distributed throughout the bra band. If the bra band is not tight enough, or otherwise ill-fitting, the bra will ultimately prove uncomfortable and unsupportive. As such, it is imperative to wear the correct band size.


The gore is the center of the cups, where the underwire forms a little bridge. The gore's position relative to the wearer's body is highly indicative of how well the bra fits. If the bra fits well, the gore should touch one's torso. If the bra fits poorly, the gore will "float above" the breasts, or not fully touch the body. Depending on the cup style, the gore may be taller or shorter; for example, the gore in a plunge bra tends to be shorter than the gore in a full-cup bra.

Side panel[]

Side panels are also known as side wings and are a key part in seamed cup styles. The purpose of the Side Panel is Side Support. This pulls the wearers tissue in from the sides and provides a minimizing, pulled forward shape. It also helps keep tissue away from the underwire and out from under the arms. The fabric used in a Side panel may vary depending on style and sometimes become more structured in fuller cup sizes to provide better results. KEY feature in SIDE SUPPORT styles.


Butterfly Collection D Cups

Bras with the same cup letter are different sizes on different bands.[6]

The cup is the part of a bra that holds the breasts. It is sewn directly onto the band, and typically has straps sewn on or able to be connected to the top of the cup (exclusion being a strapless bra).

The volume of breast tissue each cup can hold varies between cup sizes (such as C, FF, or K) on each band size (like 26, 34, or 42), in addition to bra brand or even bra cut or style. The cup size, or letter, is not the same size on differing bands; meaning if you compared a 32F and 36F bra, the 36F would have bigger cups. The size of a cup is in direct relation to the size of a band, so there is no such thing as, for example, a "D cup", since a D cup on different bands are all different sizes. However, If you compared a 32F and a 34E or 30FF, you would find they hold the same volume, though the cup shape may differ and the bands are longer/shorter. These are called sister sizes.


To determine what ones cup size may be, you would subtract the bust measurement from the ribcage measurement, and use that number to count up to the proper cup size. For example, if your ribcage measures 32 inches and your bust measures 40 inches, you would get  and would need to count up 8 cup letters. If you were trying to find your UK size, you would get  A, B, C, D, DD, E, F, FF, and should therefore start trying on bras in a 32FF.


The apex is the part of the cup which connects to the strap. The region of the cup between the apex and the band should not compress or squish tissue (indicating that the cup is too small), but should lie flush against it.




The underwire provides added support and lift to the breasts. It is a metal, sometimes plastic, U-shaped piece sewn into the bra cup that goes from the center gore to the armpits. It should completely encase the breasts; meaning the wires should be behind the breast root, not on top of the breasts. If the underwire lays on the breasts, or pokes out of the wire channel, it is a sign that the cups are too small.


The straps go over the shoulders, keeping a bra in place. It is of note that the straps are intended to keep the cup in place, not support the entire weight of the breasts.[1] If the straps dig painfully into the wearer's shoulders, then most likely the bra band is too loose or too large to be properly supportive.

If there is a ring dividing a strap into two sections, then the front portion is called the front strap and the rear portion the back strap.


Example of different types of rings and sliders. Left: Ewa Michalak Mak Nowa Koronka; Right: Cleo Karina.


The ring is the metal or plastic join (typically in the shape of a ring) that connects the straps to the band, or a non-adjustable section of the strap to an adjustable section. The more durable the material used by the ring, the longer the bra will last. Older, plastic rings that have been repeatedly washed will snap.


The sliders are the clips located directly on the straps. A strap can be shortened or lengthened as required by moving the slider. Some straps are fully adjustable, meaning the slider can move along the entire length of the strap; some bras lack full adjustability, as the slider can only move along a portion of the strap. Typically the non-adjustable region is in the front, which is thicker for aesthetic purposes.

Strap join[]


The leotard bra back illustrates the curved attachment of the strap to the band and the continuation of the strap material (the red arrow).[4]

The strap join is where the straps attach to the cup in the front and the bra band in the back. The strap join in the back is the most important. There are two types of back strap join: the camisole and the leotard, or ballet.

The camisole strap is simply a strap connected to a ring connected to a band at a right angle. This produces a more square shape in the back. The leotard strap is a strap connected to a ring connected to the band at a more oblique angle, producing a more curved, or leotard-like shape in the back.

One of the ways to identify a more supportive bra is by the presence of a leotard strap, where the strap is connected to a ring, which is attached to more strap material which is itself sewn into the band. This distributes weight more evenly throughout the band, taking weight out of the straps and the shoulders.



A typical "three sets of two" hook and eye closure.[7]

The most popular option is a hook and eye closure on the middle center of the bra's back. However, bras with closures in the front, and elastic bras with no closures at all are also available.

Hook and eye closure

In hook and eye closures, there are typically three sets of closures; this provides the wearer the ability to make minute adjustments in band size as needed, such as when a band loses elasticity or the wearer's rib cage loses or gains volume. More support comes with more hook and eye closures per set. For example, a very supportive bra may contain three sets of hook and eye closures, with each set itself consisting of three side-by-side closures. The "three sets of two" hook and eye closure is more common.


A front-opening bra.[8]


Many front-opening bras do not use hook and eye closures. Instead, plastic clasps are used to camouflage the closure.

No closure

Some bras, especially those created for sports, don't have closure.

See also[]