The very first age Goku gives out is incorrect. He informs Bulma that he is 14. In reality he is 12.
It isn’t a lie. Counting simply isn’t something he can do. Raised by himself in the mountains, the boy never picked up that 11 is followed by 12, and only after studying under Master Roshi can he put his own birthday in the correct sequence.
Treat that error as fair warning for what comes next. What with the years that vanish between arcs, the deaths, and the Hyperbolic Time Chamber quietly piling years onto a body while the calendar stays put, few numbers in the franchise are as slippery as Goku’s age. Throw Dragon Ball Super and Dragon Ball Daima into the mix and the sums get messier still.
Even so, the series scatters enough birthdays, dates and openly stated time skips to piece the timeline back together. This is where each major saga falls.
The kid who couldn’t count
Dragon Ball opens with the Emperor Pilaf saga, and it marks Goku’s first search for the Dragon Balls.
Whatever he tells Bulma, his age there is 12.
He is 12 still by the time he enters the 21st World Martial Arts Tournament and finds Master Roshi waiting for him across the ring in the final.
An entire year then goes by before anyone uses the Dragon Balls again, which places him at 13 during the Red Ribbon Army saga.
It is striking how much of the franchise flows from the actions of a 13-year-old here. Both the Android saga and Dragon Ball Super: Super Hero are built on top of it.
Three years off-screen, then Tien
Once the Red Ribbon Army has been defeated and the Four Star Dragon Ball is back in his possession, Goku leaves to prepare for the 22nd World Martial Arts Tournament. That gap swallows three years.
The fight with Tien happens at 16. Barely has the tournament finished when the teenage Goku is dragged into the conflict with Demon King Piccolo, the first occasion he is truly fighting to save the world instead of measuring himself against someone.
King Piccolo responds to his own death with a child, and handling that child eats up another three years of Goku’s life, spent training with Kami.
That makes him 19 when he defeats Piccolo at the 23rd World Martial Arts Tournament and then, notably, spares him. The bout brings the Dragon Ball era to a close and sets the tone for Dragon Ball Z and all that follows.
Twenty-four and about to die
A five-year gap separates the conclusion of Dragon Ball from the beginning of Dragon Ball Z. Raditz arrives, the Saiyan Saga kicks off, and Goku is 24.
That battle kills him. He then puts in roughly a year of training in the afterlife before being resurrected.
He has turned 25 by the time Vegeta and Nappa arrive, and 25 is where he remains for the whole of the Frieza Saga.
The chamber breaks the math
Two years on from the Namek Saga, Goku is back on Earth and encounters Future Trunks, who turns up bearing a warning about the Androids.
Another three years elapse before that danger materialises, leaving him 30 by the calendar.
Then comes the Hyperbolic Time Chamber. A single year outside, rather more than that on his body, and he finishes the Cell Saga at a physical 31.
From here on his chronological age and his lived age part ways, and they never really match up again.
Seven years dead
Seven years elapse after Gohan defeats Cell. Goku spends every one of them dead and — because he is Goku — training.
His revival comes towards the end of the Buu Saga, at a chronological 38.
Looking at him, you would never say so. Saiyans do not age the way humans do, and seven years in the afterlife left his face untouched.
Forty-two, and chasing a god
Dragon Ball Super took the place of the non-canon Dragon Ball GT, and it begins the way this franchise always begins. With a jump.
Four years, to be precise, which sets Goku at 42 for the Battle of Gods saga.
What he is after there is Super Saiyan God, partly because Beerus will otherwise wipe out the Earth and partly out of sheer curiosity about how it feels.
Every subsequent move Super makes rests on that arc.
A year on, Frieza returns, and Goku is 43.
Not long afterwards comes the Universe 6 tournament, and then Goku and Vegeta clock up three years inside the Hyperbolic Time Chamber. Their bodies register it. The calendar on the outside does not budge.
The Future Trunks Saga turns up shortly after, his chronological age unchanged from where it was.
And then he’s a first-grader again
Dragon Ball Daima is positioned after Kid Buu falls and before Super begins, and the show pinpoints its place by setting Trunks’ ninth birthday on the first anniversary of Kid Buu’s defeat. That is one year past the Buu Saga. Chronologically, Goku is 39.
His body is another matter entirely. As in Dragon Ball GT, the Dragon Balls shrink him in Daima, though Gomah does not merely wish Goku young again the way Pilaf once did. Gomah wishes Goku and his friends down to first-graders.
The man, then, is 39 while the boy on screen is seven at the oldest, wearing the very face he had on the day he told Bulma he was 14.