SpongeBob is not 13 years old, so the answer is no. SpongeBob is supposed to be an adult, according to the show’s creator Stephen Hillenburg, even though his precise age has never been established on-screen. Hillenburg asserts that SpongeBob is “old enough to be on his own and still be going to boating school.” SpongeBob would be in his late teens or early twenties according to this.
Where does SpongeBob’s age of 13 originate from, then? One explanation holds that it originates from a previous show advertising clip when SpongeBob is referred to as a “little yellow guy.” It’s possible that this isn’t a reference to his age, but rather to his little stature.
Another hypothesis is that SpongeBob’s frequent portrayal as acting like a youngster may be the cause of the confusion. He is innocent and upbeat, and he loves simple pleasures like playing with his closest friend Patrick and watching jellyfish. However, SpongeBob is not necessarily a child despite his childlike mannerisms.
Let’s move on to Gary the snail right now. Gary’s age has never been made clear in the show, unlike SpongeBob. There are a few hints that can help us determine his age, though. It is shown in one episode that Gary has known SpongeBob since he was a young child. Gary would be at least 20 years old if SpongeBob acquired him when he was in his late teens or early twenties.
It is shown in a different episode that Gary went to snail school, indicating that snails are just as intelligent as people. Gary would be in his late teens or early twenties if we suppose that snails have a lifespan equivalent to that of real-life snails (about 15 years).
SpongeBob is not 13 years old, to sum up. Although his precise age has never been known, he is supposed to be an adult. According to the information we have learned from the show, Gary is most likely in his late teens or early twenties. No matter how old they get, SpongeBob and Gary will always hold a special place in the hearts of viewers of all ages.