Board Thread:Naruto Discussions/@comment-34509017-20171024180450/@comment-3279282-20171024180913

"Contrary to the age that was given in a databook, his actual age may differ as in accordance to his academy graduation age and by statements given in the story, it had been 10 years prior to his introduction when students massacre had taken place by his hand, yet to have been a ninja himself. This in fact would render him a teen when he first appeared."

How about reading all relevant statements?