so, is he an adult or a teenager with a job. i cant tell by just looking at him and i dont think there was ever an episode that ever explained it. so what do you think?

Teen close to an adult or 21.

I think, hes a Teen, Hes a Teen but a Child at heart. 

He's a young adult, kid at heart!

He's legally 21, but he's emotionally a working kid.

He'd have to be an adult or he'd be in school (unless he 19 I guess.)

He is 21.

i read somewhere that he is 26.... :/

Well he's an adult or he wouldnt be living alone. We all know he certainly doesnt act his age, but who cares i love him anyway.

Well he does have his own house and doesn't live with his parents, so that makes him an adult.

The thing that confused me is that he's in boating school. I mean, I guess a lot of adults get their driver's licenses when they're twenty +, so Idk. And the age requirement could be different in Bikini Bottom...but yeah, I think he's a young adult.

He is probably over 21 at least, because if you notice, in the episode culture shock, the art class is at the ADULT learning center.

I think he's an adult in his 30s

If you look closely in the episode "No Free Rides" Spongebob gets is drivers licence for all of about one day and it says that he was born in 1986 which would make him 21. That would make sense since he is living on his own. Either way I still love him!

I think he is 21 he must be at least 19 because he is out of school and trying for his drivers liscense!

He is 19 .