I don't mean physically. I understand the Shiar use some weird machine to grown him into a man. But anyone out there got an idea of how old he really would have been if the Shiar hadn't messed up with his genetic code or aging, you know what I mean^^;;

I think he may be seven? It says in Uncanny Rise and Fall. Somebody does the math out loud in order to piss him off. 

i'd say around 20' maybe late

He would be fifteen.
 
@The Dark Huntress said:

" I think he may be seven? It says in Uncanny Rise and Fall. Somebody does the math out loud in order to piss him off.  "

Well, I'm not sure. Alex and Scott were in their pre-teens when the accident happened, which was when their mother was pregnant, so they should have a good 10 years on him, I think. Seeing as how Scott is in his early to mid 30's [estimation], then I think Gabriel should be in his early 20's. That's really fuzzy math, though.

Fifteen.

I'd think he'd be a Gen Xer. Like between Jubilee and Chamber in age. Now that'd be a 'What If' I'd like to see.