Naruto is a manga series from Japan. It is about a young ninja aspires to be the village leader. Naruto is seeking popularity. He has dreams of becoming the Hokage.
When part one kicks off Naruto no doubt Naruto is at the age of 12 years. Naruto is between 11 to 13 during the first part. After two years time skip he was 15. Now at the five kage summit turned he hit 16 years. At the war arc he was at 17. Then in the last movie of Naruto part 1 he turned to either 18 or 19 years.
His birthday was mentioned to have been 10th October. Remember Naruto sat for his Chunim exams at the age of 13. By the age 14 he and Sasuke left the leaf and at 16 he came back from training. He had graduated in the academy at the age of 12 since that is the age of a Ninja graduating.
In Shippuden Naruto is like 16 years. On the end of anime he is 17 years and at the end of the first series he was 19.