Well, think about the episodes when they go to school. The school is called "Peach Creek High School" so, maybe around 14, 15, или 16. With the exception of Sarah and Jimmy, who are about seven. I remember that being mentioned in an episode.
jimmy and sarah are probably,like 10 или 11....and everyone else is twelve(i know for a fact a card in eddy's wallet sed he's 12) and they're all in jr. high (middle school)