How old is Spike really?

[SergioFernandez 33]

He is the same age as the CMCs, we can see it in a memory of AJ. But he is more mature than them, we only see him interacting with children in the first season, after that he always talks to adults and teenagers. I also know that in season 6 he may already be the dragon king, (if you look at the other dragons that compete they are all teenagers/adults there is no other that looks like him) that says that he is much more mature than he seems. In dragon years he is no more than 13, but in pony years he has the maturity of an 18-year-old.

 

[SergioFernandez 33]

Another thing I forgot is that in season 8 according to Smolder he is already an adult when his wings grow, because when that happens the father dragons kick the son out of the house. Another argument that shows that dragons mature faster than ponies but age slower.

 

[dead account 2,711]

Around 15 is my guess.

[Splashee 28,566]

He acts like he's old, at least in the early episodes. In his 50s?

[ExplosionMare 18,067]

Considering how big and more "adult" sounding he is in season 9, he's probably in his 30s or 40s by now.