Finn the human fills half the Finn and Jake duo from Adventure Time. Known for his courage, the character is beloved by fans of all ages.
But after the show’s 8-year run, 10 seasons, and 283 episodes, exactly how old is Finn from Adventure Time? We have the answer right here!
Finn The Human’s Age Revealed
At the pilot of Adventure Time, Finn was a 12-year-old boy and the only human in the Land of Ooo. The Finn Sword-wielder (voiced by Jeremy Shada) revealed the age himself as he and his adoptive brother Jake (John Dimaggio) fought against the Ice King.
As of date, Adventure Time’s main protagonist is currently 17 years old. This information is divulged in the season 10 episode “Seventeen,” where Finn appears older than when Cartoon Network first introduced him.
What Season & Episode Exposed His Age?
Several Adventure Time episodes pinpointed the age of Finn the Human. If you’re wondering how old is Finn in the pilot episode, he was 12, and his best friend Jake was 28.
In the same episode where he obtained the root sword (S02E19: “Mystery Train”) in the Cartoon Network show, Finn becomes 13. By the end of S03, Pen Ward revealed Finn to be 14.
In S05E32 (“Earth & Water”), Finn’s girlfriend, the Flame Princess’ age was said to be 15, which hints at how old is Finn too because in S03E26 (“Incendium”), his best friend Jake said they were the same age. Although a few episodes prior, Finn begins second-guessing his relationship with the Flame Princess, so he builds a giant pillow fort where Finn seemingly falls asleep and visits the Pillow World.
He becomes 16 in S06E43 (“The Comet”), where Finn’s arm was lost and regained, only to lose it again. Finally, at S10E05 (“Seventeen”), Adventure Time confirmed Finn to be 17 years old.
Why Fans Find It Hard To Guess Finn’s Age
Adventure Time fans find it hard to pinpoint Finn’s actual age because, throughout the series, Finn wears the exact same thing. The main characters hardly look like they’ve undergone changes — Jake is still yellow, and Princess Bubblegum retained her look.
The only palpable change from early seasons onwards is Finn’s robotic arm. Although if you look closely, you may detect voice cracks because Finn’s voice actor is undergoing puberty in real life.
When is Finn’s Birthday?
Amidst the magical powers, daddy issues with his biological father Martin Mertens, and the long-anticipated relationship between Bonnibel and the vampire queen, there were no outright declarations of Finn’s birthday in Adventure Time.
However, Adventure Time’s executive producer and showrunner confirmed that it’s March 14.Shop The Adventure Time Collection Now
How Does His Age Progress In Adventure Time?
No definite episode described a linear progression of Finn’s age because this was not a major matter in the show. However, it would be curious to know about it before Jake and Finn end their 8-year run. But how does Adventure Time end?
As an indicator, there were several voice breakages, the deepening of Finn’s voice throughout, his willingness to marry the pillow woman named Roselinen in S05E16 (“Puhoy”), or the maturity to join the Wizard Battle to protect Bubblegum from Ice King, shows the growth in Finn’s character.
Why Some People Think Finn’s Age is 20
If the writers made him age in real-time, he would be 22 by the end of S10. However, for the sake of adolescence, Finn met an unusual timeline.
On the other hand, in S09E05 (“Elements Part 4: Cloudy”), Jake told Finn: “You’ve been coming to my shop for almost 20 years.” Given the several time skips the show introduces, it’s hard to be certain, like when Finn and Jake are dead in Distant Lands. 
Nonetheless, whether 17 or 20, Finn is still young compared to Peppermint Butler (300+ y.o.) based on Slumber Party Panic.
When did Finn turn 14 in Adventure Time?
Pendleton Ward stated in an interview that Finn turned 14 by the end of the second season, although the show didn’t mention outright when the once-grass-sword-wielding protagonist turned 14.
Is Princess Bubblegum older than Finn?
Yes, she is. Despite physically-looking 18, Ice King’s usual target is actually 827 years old. Born from a gum-like ooze from the Mother Gum, she sprouted before the show began. Although one time, Bubblegum temporarily became 13 y.o. from losing too much biomass. 
Finn’s character is a unique taste to the popular cartoon. He’s impeccably courageous for a 12-year-old but remains unspeakably bubbly even at 17, which helps captivate the hearts of Adventure Time fans worldwide.
Finn the human is 17 years old at the conclusion of the show. However, we might expect an older version of him if he makes an appearance in Fionna and Cake!
If you're looking for Adventure Time toys, we've got them here at Toynk!Shop The Adventure Time Collection Now