How old sonic is

Sonic is very old, he had many games on the Sega genesis.
Chronologically, to this year 2009, hes 18 years old his real age is unknown and un mentioned NN96

(by MarioSonicFan1)Actually he is 16 because in Sonic X he is fifteen and the show aired in 2003 which was 7 yrs ago and 1 year in our world is 1 month in their world so in their world that would be 7 months ago. And in one episode, in Chris' world (our world) it had been 6 yrs since sonic had left; although in Sonic's world it had been 6 months. So 6+7=13 which would be 13 months since sonic left, including the other months they spent fighting the meterex which would have taken around 6 months. So, 13+6=19 which means sonic is 16 yrs and 7 months old. He'll be 18 in about 15 more of our years/their months