How old are the characters in Undertale?

Undertale: How Old Are the Characters?

Written by:
Avatar photo
Rhett Roxl is a professional writer who has been gaming for as long as he can remember. He merged both passions together to become a writer in the game industry in 2020.

Reviewed by:
Avatar photo
Marshall is a seasoned writer and gaming enthusiast based in Tokyo. He's a prolific wordsmith with hundreds of articles featured on top-tier sites like Business Insider, How-To Geek, PCWorld, and Zapier. His writing has reached a massive audience with over 70 million readers!

One of the things that make Undertale so compelling as a video game is its characters. They’re so compelling, in fact, that even the characters’ ages are being talked about by the community. Allow us to chime in.

Table Of Contents

    How Old Are the Characters in Undertale?

    First things first, it should be noted that there is no official or canon record of the characters’ ages in Undertale. Be that as it may, the fact that there is no canon record of this makes the discussion itself all the more fascinating. We can simply look at the facts the game presents to us and formulate our own assumptions.

    That said, the best thing we can do is make an educated guess as to what each character’s age is. Each character has characteristics and other details that hint at experience and personality that come with age. With every detail we can gather about each character, we can then deduce how old they are. Let’s get started.

    Undertale Character Ages Chart

    As mentioned, there’s no official record of the ages of the Undertale characters. The items below are assumptions based on various factors. Read the details of each character below the table to learn how we came to these conclusions.

    Chara~10-13 when she first fell into the Underground; ~40-50 when she appears in the Genocide route
    Annoying Dog~24 (~136 in dog years)


    Frisk from Undertale.

    Frisk is the protagonist of Undertale. They’re the eighth human to fall to the Underground. During the events of the game, Frisk’s appearance is that of a young child, though not old enough to be a teenager. If they are, there’s a very good chance that they’re on the younger spectrum.

    Although controlling Frisk is something we can attribute to plain video game mechanics, it can also be a sign of being impressionable if we take lore into account. Depending on the player’s choices, Frisk can either be a genocidal maniac or a friendly pacifist.

    Frisk is also not young enough to still be interested in toys, as shown when interacting with the toys all around Toriel’s cabin.

    We can expect Frisk to be around 12 to 15 years old.


    Chara from Undertale.

    Chara is the first human to ever make their way to the Underground. Chara’s appearance is very similar to that of Frisk. When Chara arrived at the Underground, their age couldn’t have been more than 14. With that assumption, Chara might have been around 10 to 13 by the time they made her way to the Underground.

    However, as noted by Asgore, Chara fell to the underground “long ago.” It isn’t clear how long ago exactly, but by the time Chara fell to the underground, they were about the same age as Asriel, Toriel, and Asgore’s biological child.

    We do know that it’s been long enough that most monsters in the game don’t even know what a human looks like. Even characters like Papyrus and Undyne have never seen a human before. Frisk is the eighth human to fall to the Underground and Chara was the very first one.

    On the other hand, every other human who has fallen since Chara may have just been abducted by Asgore immediately, which is why none of the other monsters in the Underground have seen them.

    That said, a human falling to the Underground could be an event that only happens once or twice every decade, more or less, as it is eventful enough to be a big deal, but not too rare that it is almost like a myth. We can then surmise that Chara may be 40 to 50 years old by the time they show up at the end of the Genocide Route.


    Sans from Undertale.

    Sans is one of the most enigmatic characters in Undertale. Though aloof, playful, and obviously kind-at-heart, there’s more to Sans than he’s letting on.

    Sans as the final boss, if you follow the Genocide Route, is arguably the toughest enemy in the game. This means Sans has the most experience when it comes to combat. He’s also the only character in the game who can seemingly appear and vanish out of thin air.

    Sans also has an affinity for science and may have been a scientist back in the day.

    Sans also has a very close relationship with Toriel, which implies the two have known each other for a very long time.

    When speaking of his past, Sans always refers to those memories and moments as “a long time ago.” His apathetic nature could also be a result of him being too old to care about the more minute things. This is all very hypothetical, but there’s very good reason to assume Sans is at least 50 to 100 years old, if not more.


    Toriel from Undertale.

    Toriel is the character that saves you from Flowey. She is a very endearing and caring mother figure and we later find out that she used to be the queen of the Underground.

    Toriel is unable to keep aging anymore since the only way for monsters to actually age is to have a child. However, we can safely assume that Toriel is incredibly old since she was there to care for Chara when she fell to the Underground all those years ago. It is said that Toriel was also already living when the war between the humans and the monsters happened, which is a consequential event that happened a long time ago before the events of the game.

    That said, we can easily surmise that Toriel should be at least 50 to a hundred years old, if not more.


    Asgore from Undertale.

    Asgore is the king of the Underground. He was also there to fight in the war between the humans and the monsters all those centuries ago. We can safely assume that Asgore’s age is close with Toriel’s, his ex-wife and the former queen of the Underground.


    Asriel from Undertale.

    Asriel is the only son of Toriel and Asgore. When Chara fell to the Underground, both of them were around the same age, but it is not known which of them were older. Like Chara, Asriel must have been around 10 to 13, if not younger, during that time.


    Papyrus from Undertale.

    Papyrus is Sans’ brother. His biggest dream is to join the Royal Guard, which is why he is so keen to capture a human. As the game progresses, Papyrus is held back by his clumsiness and kindness. Whenever he tries to capture Frisk, he either accidentally makes a trap too easy or he simply draws them back because they’re too deadly.

    It is very likely that Papyrus is younger than Sans, perhaps way younger. We’ve already surmised that Sans could be hundreds of years old. Papyrus, on the other hand, may not be older than 20.

    It is theorized that the events of the game are set in the year 2015, which is also the game’s official release date. Papyrus’ UnderNet account name is CoolSkeleton95. A lot of people have theorized that 95 could allude to Papyrus’ birth year, which would be 1995. If both of these theories are true, then Papyrus should only be 20 years old during the events of the game.

    Papyrus being 20 years old is very sensible when considering his actions and motivations in the game. Papyrus is young enough to have dreams that are motivated by shallow things. He aims to achieve his dreams of becoming a member of the Royal Guard. But the only reason why he wants to become one in the first place is to make his mentor proud, make friends, and become popular.


    Undyne from Undertale.

    Undyne is the leader of the Royal Guard, Alphys’ love interest, and Papyrus’ friend and mentor. She is tough and full of conviction, but she also has interests that show signs of her being young-hearted. Apart from honing her skills in combat, she is also very into anime and cooking.

    Like Papyrus, Undyne also has an UnderNet account, which is named StrongFish91. If we’re to follow the same theory we enforced on Papyrus, there’s a chance Undyne is only 24 years old during the events of the game.


    Alphys from Undertale.

    Alphys is the Royal Scientist and the creator of both Flowey and Mettaton. She is a brilliant scientist, especially for her age. Or at least, her age that we believe.

    Alphys’ success in her career hints that she is old enough, but her fascination with Undyne and her overall demeanor can also hint that she’s not that much older than Undyne, if she’s even older.

    That said, we can assume that Alphys could be around 24 to 30 years old.


    Flowey from Undertale.

    Flowey is the sinister plant that you meet when you first start playing Undertale. You also end up fighting this creature at the end of the game, although the difficulty of the fight depends on the gameplay route you took.

    It is later revealed that Flowey is in fact the soulless version of Asriel, Asgore, and Toriel’s only biological child. Asriel eventually fell at the hands of humans. His remains got scattered on a garden of golden flowers, the place he stood on before finally perishing.

    Flowey came to be as a result of Alphys’ experimentation with souls and determination, which revived Asriel as a sentient, soulless golden flower.

    That said, although Flowey is an iteration of Asriel, who we believe was born hundreds of years ago, he was ultimately created by Alphys only when she became the Royal Scientist, who is relatively young. There’s a very good chance Flowey is only around 5 years old, with a heavy emphasis on being more or less than that. Despite this fact, due to being the essence of Asriel, Flowey could still be considered around 40 to 50 years old.


    Mettaton from Undertale.

    After creating a soulless creature with Flowey, Alphys finally managed to create a creature with a soul with Mettaton. Mettaton is an entertainment robot who is as soulful as he is entertaining. Even when he is attempting to kill you, it is later revealed he only did so so that Alphys could rescue you, which in turn would give Alphys a sense of importance. It’s psychopathic, but the robot means well.

    Since Mettaton is the creation of Alphys and she only created him after creating Flowey, Mettaton couldn’t be older than 5 years old.

    Annoying Dog

    Annoying Dog from Undertale.

    The Annoying Dog isn’t really a character that’s consequential to the overall story of Undertale. Instead, this character is simply a representation of Toby Fox, the game’s creator. The Annoying Dog pops up from time to time, often causing chaos and mayhem.

    Since the Annoying Dog is a representation of the creator of the game, and Toby Fox was born on October 11, 1991, that means the Annoying Dog was around 24 years old when the game was released, or 136 years old in dog years.