how old is ash?

Probably 14 in the TV series by now. We saw him at the first episode as a 10 year old boy when he got Pikachu. In the 3rd Pikachu short movie, Ash gave Pikachu a cake as an aniversery present of the day they met. Calculate that up, you get Ash Ketchum is 14 years old. (1 pokemon world year= 3 seasons of Pokemon)

Deff. around 14! ^^ ☺

We don't really know...

Some people think he's 13 and can argue for that. Other people think he's 14, 15, 16, ect.

As mentioned above we can atleast say that he's over 11, since they celebrate his (and Pikachu's 1 year anniversary) birthday in a short film.

Other than that, we can't say how old he is. Or at least, we can't be sure before Nintendo or the series tell us.
One region could've been faster, or slower than the others.
Still, we've only seen Ash celebrate his birthday one time, but at the same Ash is the ONLY main character we've seen celebrating his birhtday.

Sorry, I got a bit caught. =D
Myself, would guess he's somewhere between 12 and 16.

I don`t think he gets older. I have heard that.