A bra extender is a small item which is used to span a sizing gap between two sides of a bra closure. This item is used almost exclusively on bra back closures instead of front closure. If a woman were to purchase a bra only to find that, while the cup size was correct, the band did not fit properly around her rib cage, she may need to purchase a bra extender to make the bra fit properly. Some women use bra extenders on a regular basis because they find it difficult to buy pre-fabricated bras that fit them properly. These items can also be used by women who regularly fluctuate in weight.

 While it is most common for bra extenders to be designed to fit into the backs of bras, there are a number of design variations. Bra closures are made up of a series of rounded hooks that fit into loops. A bra extender simply offers an extra row of these hooks and loops. Some bras are designed to close with just one hook and loop while others close with as many as four hooks and loops. It is more common for bras to close with two or three hooks and loops.

 Just as there are variations in the number of individual closures that are built into a bra, there are also variations in the design of bra extenders. There are bra extenders that can be used with bras that close with two hooks as well as those that close with one, three, and even four hooks. Bra extenders are generally available in a limited number of colors. The most common bra extended colors include black, white, and nude.

 Some women use bra extenders when they are pregnant so that they can accommodate the changing shape of their bodies without having to purchase new lingerie. Furthermore, bra extenders can be useful in wardrobes for stage and film, as these items can help them to create perfect fits for the actresses using the costumes. A person shopping for a bra extender may be able to purchase such an item from a store that sells fabrics and other kinds of garment closures.