Juliet is thirteen years old. When she meets Romeo, he is around seventeen and she is twelve. She says that she has known him since he was nine, but she does not specify how long ago that was. Some people believe that Juliet is around sixteen or seventeen years old, based on her maturity level and the fact that she appears to be around the same age as her cousin, who is eighteen. However, some people also believe Juliet could be younger than sixteen because of the way she acts and speaks at times throughout the play. In Romeo and Juliet, it’s clear that Juliet is younger than her Nurse, who is at least forty years old. She also appears younger than her cousin Tybalt, who is around eighteen years old. Even though she’s young, Juliet acts maturely for her age and even seems more mature than Romeo at times! The fact that she makes such quick decisions (like marrying Romeo) shows us how wise beyond her years she really is!