How much Charisma does a mage need to summon 3 golden dragons?

My Charisma is 27, but I can only summon 2 golden dragons.

I think you are gonna need help from items like Mambo hat/coat, jet black crystal ball, and there are also amulets and oh, a cha t-shirt too that you can buy in feather town. EDIT: Also note there are also elixirs you can hunt down that will give you 5 bonus points too. If you don't get the right stat don't worry, you can reset the point from it later using a special candle. 

Thank you for your reply. I just want to know the specific values. For example, a mage with 9 points of charm can carry 1 monster, and with 18 points of charm can carry 2 monsters. A fairy with 6 points of charm can carry 1 monster, and with 12 points of charm can carry 2 monsters. If you want to carry 3 monsters, how many attribute points are needed?

gold dragons require 12 charisma each

some classes have bonus "hidden charisma"

royal & mage: 6

elf: 12

so you would need 3*12-6 = 30 cha

Thank you so much for your help, as I've only been playing for a week.