285cc Need Advice for Full C Look? (photo)

In order to make an accurate size recommendation, I would need to assess your chest wall and breast mound measurements and characteristics.  Unfortunately, there is not a general rule of thumb or objective criteria to implant selection.
Your plastic surgeon will perform several measurements of your chest wall and breast anatomy and determine a range of implants that both fit your chest wall and reach your desired goals.
The next step is to try on this range of implants in the office with your doctor.   The key to this success is showing your surgeon the body proportion you desire with a bra sizer and allowing your surgeon to guide you to the right implant.   It will be much easier to communicate in implant cc's than cup size when determining the appropriate implant for you.
I wish you a safe recovery and fantastic result.
Dr. Gill

Most plastic surgeons will want to limit implant choice to use of an implant that is no wider than your own breast width. There is good reason for this--wider implants often give results somewhere between unnatural and bizarre. 

We usually don't like to quote cup size, because there are no fixed definitions. Many surgeons on these pages estimate an expectation of one cup size elevation for each 150-250 cc. A 285 cc implant by those estimates should give about a one and one-half cup size increase. 

Rather than guessing cup size, I find it useful to have patients try on implants and use visualization to choose an target, and pick an implant size based on that, using the woman's anatomy as a limiting factor in some patients. If you are worried about ripples, use silicone implants, as rippling is less common with those.

Thanks for your question, best wishes.