12-Kaido is probably about 50 years old since he was part of the legendary Rocks Pirates just as an apprentice.
13-Benn Beckman, 50 years old
14-Kuzan, 49 years old
15-Dracule Mihawk, 43 years old
16-Blackbeard, 40 years old
17-Kozuki Oden died at 39 years old.
18-Shanks, 39 years old
For further comparison, Luffy is only 19 years old, while Zoro and Sanji are 21 years old.
Luffy is so much younger than his rivals!