As far as immortal supernaturals go, Klaus (Joseph Morgan) is pretty ancient. He’s over 1,000 in hybrid years! But how old was Klaus when he became a vampire?
Born in the 10th century to Esther (Alice Evans) and a werewolf, Klaus was raised by his mother and Mikael, the witch’s husband. The family had moved from the Old World to a village that would become Mystic Falls, living amongst werewolves. Klaus was a middle child, having older brothers Finn and Elijah (Daniel Gillies), a younger sister named Rebekah (Claire Holt), and two younger brothers, Kol (Nathaniel Buzolic) and Henrick.
The siblings all became vampires at the same time, except for Henrick. His death spurred Esther and Mikael to turn their children. Rebekah was a teenager at the time, while Elijah and Finn were presumably in their late ‘20s. Obviously Klaus falls somewhere in between them, but his exact age is never explicitly mentioned.
Joseph Morgan was 29 when he was cast as Klaus, but that doesn’t necessarily mean anything. Paul Wesley (Stefan Salvatore) plays a 17-year-old vampire, and he’s 30!
Damon (Ian Somerhalder) is supposed to have been around 22 when he turned. We’ll assume Klaus is a bit older than him — but not too much. It can’t be that creepy when he hits on 18-year-old Caroline (Candice Accola).