I wear a ring size 7, what is the best ct size for me in your opinion?

i wouldn't go bigger than 1ct, my sister is a 6 1/2 and has a 3/4ct and it looks beautiful on her... dont just look at size either! my mother's ring is 1/2ct and is worth double my sisters because of the cut/color and the quality. Size isnt the only thing relative with diamonds. I'd rather have a perfectly cut colorless diamond than a huge dull one