roughly 28" for a 54" round. Hanging roughly 32" above the table top to the bottom of the chandelier.

Your welcome... You could easily do a pinch smaller.... 28" is a good size light especially if you have high ceilings and or a larger room. I have a 60" round with a 32" it is a bit oversized, but I like it a bit larger vs. smaller in scale.

Good luck.