Is there a big difference between an 800cc HP silicone implant and a 900cc HP saline implant, both round?
A 100cc difference in implant size amounts to a little under 1/2 a cup size difference. The other factor when you go up in implant size is that the width of the implant increases with a greater size. You can get to a point where the implant is too large for your chest and will make the breasts appear too wide for your chest. Your surgeon should be able to discuss these factors with you when deciding on the best implant size for you by checking the implant measurements versus your chest width. Keep in mind that the larger implants are more heavy and put more stretch on the skin which can lead to thinner skin. Good luck!