Sizing
is based on the Golden Rule called PHi
This is the ratio calculation PHi (1.618)
Here is a
simple calculation to consider
1- (.618) =
(.382) ie 38.2%
This keeps
within the Golden Rule of Phi
18" medallion
x 1.38 = a 25 inch medallion
No rules rule so
select 29", 25" or what ever matches your design. 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