I think he's at least 6500 years old, but most likely a lot older. He was born sometime in the first age, so we can't pinpoint exactly how old he is, but the years of the seconde and third age add up to 6462. He was an adult before the sack of Doriath, so he was at least a century old then, and there was about 90 years between the sack and the end of the first age. So that means he was at least 190, but I think he was older. Anyway, added together, he is at least 6652.
