The tape should just skim the bra in front. Step 3: Calculate to find your cup size If you're still wondering: "What is my cup size?" All you need to do is a little bra math: Subtract your band size ...

First, let’s go over the basics. Your bra size is made up of your band size and your cup size. According to British lingerie brand Katherine Hamilton, the band size refers to the size of your rib cage ...