Simple Answer:
Keeping in the design principles of Phi, "the golden rule"
there should be a 1/3rd to 2/3rd
ratio.
Example:
Widest point of the chandelier is 18" (45.7cm)
Multiply x 1.618 = 29" (73.6cm)
<= For more
read the article
Always
remember that when you view the medallion mounted on the
ceiling it
will appear much smaller from your perspective at a lower level.
By
selecting one that uses the golden rule calculation, it will appear
to
be the
right size with the correct visual distortion.