1. Zac Efron at 18.
Zac Efron now at 31.
2. Joe Jonas at 18.
Joe Jonas now at 29.
3. Vanessa Hudgens at 18.
Vanessa Hudgens now at 30.
4. Miley Cyrus at 18.
Miley Cyrus now at 26.
5. Selena Gomez at 18.
Selena Gomez now at 26.
6. Hilary Duff at 18.
Hilary Duff now at 31.
7. Raven-Symoné at 18.
Raven-Symoné now at 33.
8. Dylan and Cole Sprouse at 18.
Dylan and Cole Sprouse now at 26.
9. Brenda Song at 18.
Brenda Song now at 31.
10. Shia LaBeouf at 18.
Shia LaBeouf now at 32.
11. Ashley Tisdale at 18.
Ashley Tisdale now at 33.
12. David Henrie at 18.
David Henrie now at 29.
13. Corbin Bleu at 18.
Corbin Bleu now at 30.
14. Aly Michalka at 18.
Aly Michalka now at 30.
15. Danielle Panabaker at 18.
Danielle Panabaker now at 31.
16. Jake T. Austin at 18.
Jake T. Austin now at 24.
17. Moisés Arias at 18.
Moisés Arias now at 24.
18. Jason Dolley at 18.
Jason Dolley now at 27.
19. Nick Jonas at 18.
Nick Jonas now at 26.
CORRECTION
Hilary Duff is 31. An earlier version of this post misstated her age.