Fantasie uses UK bra sizing, and the size range varies across collections. Many styles are designed with fuller busts in mind, but a well-fitting Fantasie bra should still sit level around the body, have cups that enclose the bust comfortably and provide support without straps doing all the work.
Start with your usual UK bra size rather than automatically changing band or cup. Fit can differ between a side-support bra, a plunge and a moulded spacer style. At Ouh La La we can help you compare styles and sizes with professional bra fittings in our Haywards Heath boutique. Online, use our size guide and any available product-page fit guidance.