Size 42ddd breasts, if I get 500g taken out what cup size will I be after?

At
size 42 each 300 grams corresponds to 1 cup size change.If you removed 600 grams you would go down 2
cup sizes to a 42 D.However, at your
height and weight, it is possible that insurance companies will require as much
as 1 kilogram to be removed.In that
case, you would be a size C.I recommend
a new technique called The Ultimate Breast Reduction™.The breast tissue is reshaped creating upper
pole fullness, elevated higher on the chest wall and more medial to increase
your cleavage.The weight of the breast
is transferred to the underlying muscle resulting in immediate pain relief
without excessive reduction.This
technique avoids the ugly vertical scars of the traditional technique,
maintains nipple sensation and the ability to breast feed.Best Wishes,Gary Horndeski, M.D.

Thanks for your question and post.  Photos would be very helpful.  In general every 250 grams of breast tissue correlates to one cup size.  You should discuss your goals with  your plastic surgeon and in this manner you will meet your expectations.  

Cup size does not always correlate with volume removed but assume a cup size is about 200 cc's on average. best of luck.