The most important factor in determining what size implant to get is how wide your breast width is. After this it is important to know what kind of look you want and approximately how big you would like to be. It is better to know how big by using sizers in your bra in the office and not using cup size. Cup size is like dress size. There is no standard to these measurements and it is much better to know the volume in cc’s. Your plastic surgeon can advise you well knowing your measurements. Also there is little difference between 50cc or less. I usually advise people if there are deciding between 2 sizes and they are only 50cc difference they would in general be happier with the bigger size. If they are deciding between implants that are 100cc or more difference then the measurements need to be considered carefully.