April 16 is a huge day for the Dragon Ball fandom. Son Goku turns one year older, and it looks like all the fans are surprised and confused regarding the Saiyan’s age.
The date marks our hero’s canonical birthday, and things get a little tricky from here. If one goes by the manga, Goku had been born in Age 736, but anime seems to claim that he was born a year later but on the same date. For all canonical reasons, the fans are basing Goku’s age on the year in the manga.
Dragon Ball timeline has now caught up to Age 780, and this franchise had recently wrapped its ‘Universal Survival’ arc. If this timeline is correct, then the Tournament of Power starts in 780 and Goku is biologically 44 years old. This figure does not really account for the years he had spent dead and working in the Hyperbolic Time Chamber.
When it boils down to his death, Goku is familiar with the shtick since he has died more than once. This Saiyan had died after the fight with Cell, and Goku then stayed like that for 7 years much before he had been revived for a World Martial Arts tournament.
This hero also spent many years at Hyperbolic Time Chamber which might or might not have physically aged the character. If one does choose to add these years to Goku, then he is close to 50 years old.
Most fans agree that Goku is in his 40s and they ignore the time that passed while he had been dead. This character has not aged a lot any since his appearance in Dragon Ball Z. For Saiyans, the long lifespans add to slow aging, and Goku had learned that his race will stay in their prime until they are 100.