Try the A Bra That Fits Calculator to get an accurate size and also be mindful of your shape—shallow versus deep, wide-set vs narrow, fuller on the bottom vs the top, etc—because that can affect how different bra styles fit you. Check out Bratabase to see photo examples of how the same-sized bras fit on different women! I buy bras new or gently used on eBay and Poshmark or at Nordstrom Rack because I always want to get a deal.