Was Naruto's age stated somewhere in the manga, in Part I?

[Takos]

Was there anywhere in the manga (NOT databooklet) in Part I stated how old Naruto was? Or anyone else from his class, since they were the same age?

I know in Part II Naruto told one of his parents, if I'm not mistaken, his age, but I'm curious about Part I.

If so, could somebody please give me the chapter and the page?
Thanks.

 

[MacMiller]

Do you only want to know his age, or just if they stated it as a fact somewhere?

 

[gordo1]

He was 12/13. He was gone for 3 years and everyone keeps saying 16 years ago about the kyuubi incident.

 

[Takos]

Just if Naruto's age was stated somewhere in the manga, in Part I.