Quote Originally Posted by dvoraen View Post
Keep in mind that Bahamut may well have been artificially inflated in size. The Final Coil of Bahamut kind of implies this. I'd say the 'real' Bahamut would have been about the size of the large dragon we see in the Tour of the North video.
if your referring to T13 the burning heart no that is not his real size that is merely his essence on his crystal heart.

Also keep in mind Vishap wasn't even a great wyrm just a very big dragon now we take that into account and relies that Bahamut is one of the first broad the size of him being about the full size of Mor Dhona is about right. Also don't forget a primal to come into being needs 3 things crystals prayers and a mass of Athear now if we take into account the whole Dragons of Meracidia into account that is enough to summon a big entity it took the whole realm of Eorzea to summon the Twelve in Cartano to attempt to seal him.