How old is John in Peter Pan?

In J.M. Barrie’s original play and novel, John Darling is depicted as being around 12 years old. He is the middle child of the Darling family and is often portrayed as sensible and protective, particularly towards his younger sister, Wendy, and his baby brother, Michael. John’s age is essential as it highlights the innocence and imagination of childhood, which contrasts with the themes of growing up and the desire to remain a child that are prevalent throughout the story.