Does 520cc on a 5ft 3, 155lbs, age 25, size 34A sound too big? (Photos)

After I measure and discuss goals with my patients, we then look at pictures of women with similar measurements with different size breast implants. My patients tell me that this process is very helpful in determining what size breast implant is right for them. 
Dr. Ted Eisenberg, Board Certified Plastic Surgeon and Author      
RealSelf Distinguished Hall of Fame Inductee

The 3D imaging should be very helpful for you in choosing size.    Based on your height and weight, and the fact that you are only in your 20's, 520 cc is large, and you may regret having selected it in the future after pregnancy and/or gaining weight.     Implants in the larger range tend will have more impact on the skin, with stretching and sagging of the lower portion of the breast.      Don't be fixated on cup size, but focus on the look.     I think you would have an excellent result with something in the mid 400 range.     It is easier to go up in size in the future than to go down in size.    Good luck.   

Good afternoon!Given your photos and goals, I think the 520cc would be more than you want- try the 425-ish size. I would be hesitant to use a Moderate Profile implant, however, because they are way more flat and wide compared to your goal photos. I would go at least Mod Plus!