I love this form as it is soft and a great shape, sticks enough to stay in place with a normal bra, and is comfortable and feels like part of me. The Breast Form Conversion Chart sizing seems fairly accurate, as I have a size 9 in a 34E bra which fits perfectly (although another 34E bra seems like a size 8, as the chart suggests, would have fit better). I'm 35" underbust and 41" over, which works out as 34E or 36DD. The Bra Size Calculator (35" under, 20.5" half over) suggests a 40A, which is sister sizes with a 34D. Taking this to the chart suggests a size 6, which is what I ordered initially, but it seemed more like a 34A or B, so I decided to go 3 sizes bigger. I think maybe the sizes depend on your chest size/shape somewhat, so I'd suggest requesting a trial form (via email/chat/phone) as they are available even if the site says they are all out of stock. Very very happy with this form, and for the help and service from Amoena.