What age is peter from Narnia?

Peter is 13 years old when he appears in The Lion, the Witch and the Wardrobe. As a monarch of Narnia's Golden Age, he rules with his brother and sisters for 15 years, reaching the approximate age of 28 before returning to the age of 13 in England at the end of Wardrobe. By The Last Battle he is a 22.In Prince Caspian he is 14 years old. He was born in 1927.