Your “Sister” Bra Sizes & Your Bra Size Neighborhood

VIDEO TRANSCRIPT: "Bra Fitting Secrets: Your Sister Bra Size" Length: 2:05

Every bra size has a set of sister bra sizes – those sizes that surround a bra size and vary only slightly. It’s good to know what they are and how they differ because, when you feel it’s time for a bra size change, you can quickly figure out which new bra size you need to try. So let me show you sister sizing and how it works. For this example, I’ll use the bra size 36C.

Moving vertically will simply change your cup size while leaving your band size the same. Want a bigger cup? Move down to a 36D. Want a smaller cup? Move up to a 36B.

If you just want to increase your band size, going diagonally will change your band size while keeping your cup size the same. Now this probably doesn’t seem right. Most women think moving from a 36C to a 38C, horizontally, would be the answer. But in bra sizing, when you go up a band size, you need to go down a cup size if you want to maintain the same cup volume. So, a 38B will keep your cup volume the same while giving you a bigger band, and a 34D will keep your cup volume the same while giving you a smaller band.

Moving horizontally changes both your band size and your cup size. As I explained earlier, when you go up a band size, you need to go down a cup size to maintain your same cup volume. So, moving from a 36C to a 38C gives you both a band and cup increase. Moving from a 36C to a 34C decreases both your band and cup size.

Understanding your sister sizes and knowing which ones to choose when your body changes, pretty much guarantees you’ll stay in the correct bra size throughout your life.