How old is masterchief?

Answer 1

Oficially he's about 42 (earth) years old. However during slipspace (faster than light) travel, he, along with most other people aboard a ship, are put into cryogenic stasis. This stasis almost completely stops all cell generation, and degeneration, so a person's body does not physically age while in this state. Considering slipspace travel can take anywhere from a couple days, to about 6 months, it is difficult to say how old his body really is. You can assume though, that it is at least in the early to mid thirties.

By what Halopedia says, he's 21 year old in the standard 21st century time.

http://halo.wikia.com/wiki/Master_Chief#Age

If the year he died is 2553, and was abducted at the age of 6 in 2517, then he is 36 years old.

Answer 2

"Master chief is around his 20s-30s. Im guessing cuz his voice sounds young"

Really, The MC is 41 years old during the events of Halo 2 and Halo 3. Seeing how MC was born in the year 2511. If you were to subtract 2552 and 2511 you would come up with 0041. So he is 41 years old.

Answer 3

We are never told how old Master Chief really is.

Masterchief is a human, though, and his "suit" can make him do out-of-the-ordinary things. This makes it hard to tell how old he is, but I would have thought around 40, judging by his voice.

Glitches show an alien face covered in scars. I would like to inform you that glitching is not an actual way of seeing his face. It is just randomage.