Cup Sizes: How Are They Determined?
As you probably know, your bra size is a combination of your band size (an even number) and your cup volume (a letter). Your band size is determined by the actual measurement of your ribcage, or, the area right underneath your breast where it hits your chest. We’ve talked before about how to make sure your band feels snug, but not too tight so that you have a proper fit. But what about your cup volume? It’s a tricky one to determine, but we’ll break it down for you in this blog so that it’s easier to understand.
Every cup size (D, E, F, etc…) is qualified by a specific cup volume. What does that mean? It means the amount of breast tissue that can fit inside of a cup. Remember science class where you learned how to calculate volume? A square is easy: length x width x height. But what about a bra cup, that has a much more organic shape and is made out of a material that bends and moves with your body?
At Trusst, we’ve done a lot of work on the back end to calculate the volumes of each cup size that we make. We’re backed by science, so you can bet that this work contains a lot of formulas, computer modeling, and testing. Here’s a handy chart to help you understand the volumes of each cup size, with its equivalent weight (for fun!)
We’ve talked about sister sizing before, but in a nutshell, sister sizing means that one cup volume will work with multiple band sizes. For example, a 38G is a sister size to a 40F(DDD), because they both have the same cup volume. So if you find that your cup fits but your band is too tight, you might want to try the sister size. Make sense?
How to make sure your cup volume is correct
We’ve also talked a lot before about how to make sure your bra fits. If your cup volume is correct for your breasts, you should not see any gaping or spillage on top of the cups. If you feel gaping, you might want to go down a cup volume. If you feel spillage, you probably want to go up!
Size Calculator + Bra Experts
It’s really hard to determine the exact volume of each woman’s breasts, because every body is different (and no two pair of boobs are the same!) However, we’ve broken things down to be a lot easier for you to find the right cup size, just with two easy measurements. Our Size Calculator is programmed to work specifically with Trusst bra styles. And if you have any more questions on sizing, cup volumes or our bras, one of our Bra Experts is always available to help you!