34D - What Bra Size Would I Be if I Got 750cc Breast Implants?

Starting off at a D cup, I would caution against an implant this large.   Generally speaking,larger implants increase the risk of complications such as implant malposition, which can be very difficult to correct longterm.  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

At 34D, why do you feel you need an augmentation? 750cc implants are enormous implants. With the combination of these implants and your current size, you would be entering the realm of the "pick a letter of the alphabet" cup size. F, FF, GG... I would recommend that you seriously reconsider why you are choosing such large implants.