First, you need to get a proper bra fitting, whether it’s at your local shop or at a big name department store (don’t worry, it’s almost always free). Many fitters use a measuring tape to find your size, but the most important part of the process is to actually put on the bra. “Bra fitting is an art, not a science. The only way to properly fit a bra is to try it on,” says Koch.

Also, keep in mind that, just like clothing, not all sizes are equal. Even if they sport the same number and cup size, the fit can vary due to brand, manufacturer, and where the bra was made. “Every bra company tends to cut their bra differently — especially if they’re from different countries,” says Koch.