What is ideal dimension size for a home listening room?


Is it a cozy size, large living room, 10 x 15, 20 x 30, some where in between?  I guess it shouldn’t be square.  Let’s assume ceiling is 7 1/2.  Heard ceiling height means a lot.
emergingsoul
You could use the Golden Ratio of 1:1.62 to get an idea of the "ideal" dimensions.
So for 15' wide: 24' long.
Dudes, I just measured my room. My ratio is 1:1.63. 14 Karat gold? Or 24 Karat tin?
I would be solving for reverb time and at least a 9’ ceiling before I got too worked up over  ratios....
Magic, numbers I don't know.  The best I've heard was not a room.  It was an ampa style indoor theater, in Aspen, Colorado. Back wall retracted.  That was a wonderful, setup.. Krell.

The worst 8x8x8, 9x9x9, 10x10x10. 

Regards