How Old Is Luke In Episode 4

43 rows older sources put luke and leia at either 18 or 20 years old at the time of episode iv, but we now know that they are born in episode iii, which takes places 19 years before. Luke skywalker was supposed to be 21 in episode 4 and princess leia was only 18 for the movie. In episode 4, luke is 19 years old. And since he and leia are twin brother and sister, they are the exact same age. They were 22 in episode 5 and 23 in episode 6.