Goku's age varies depending on whether you consider his chronological age (actual years since birth) or his biological/physical age (how old he appears or is physically due to training, time spent dead, or time dilation effects). Here is a summary of Goku's age at key points in the Dragon Ball timeline:
- At the start of Dragon Ball Z, Goku is chronologically about 23-24 years old but physically 23 due to time spent training in the afterlife
- During the Android and Cell sagas, Goku is around 27-31 physically and 27-31 chronologically, factoring in training in the Hyperbolic Time Chamber which compresses time
- At the end of the Buu saga, Goku is about 37-38 physically and 44 chronologically, as he had been dead for seven years and then a 10-year time skip occurred
- Dragon Ball Super takes place during the 10-year gap after Buu's defeat. Goku starts Super physically around 31-32 and chronologically about 38-39 years old. By the end of Dragon Ball Super: Broly, he is physically 32 and chronologically 39
- In Dragon Ball GT, which is set five years after the end of Z, Goku is physically 42 but chronologically 49. However, he is turned back into a child (physically 11-13) by the Black Star Dragon Balls but retains his adult mind
- According to some sources, at the end of Dragon Ball Z, Goku is chronologically 47 and biologically about 43. In the Dragon Ball Super: Super Hero movie, he is about 45 chronologically and 41 biologically
In summary, Goku is roughly in his late 30s to early 40s chronologically by the end of Dragon Ball Super and early 40s biologically, but his physical age can vary widely due to time spent dead or time manipulation. In Dragon Ball GT, his physical age is younger due to the plot device of being reverted to a child. So as of the latest main continuity (Dragon Ball Super), Goku is about 39 years old chronologically and physically around 32 years old
