Checking the ages of the Cousins Beach crew is basically a full-time job for the fandom because, honestly, the timeline moves fast. Between the books and the Prime Video series, things get a little blurry. People are constantly asking how old are they in The Summer I Turned Pretty because the transition from "kid" to "adult" is the whole engine of the story.
Belly Conklin starts the series as a fifteen-year-old on the cusp of everything. You know that specific age? When you’re too old to play with toys but too young to drive yourself anywhere meaningful. That’s her. In Season 1, she’s 15, turning 16. It’s that pivotal "pretty" summer where the boys finally stop seeing her as the annoying little sister and start seeing her as, well, a romantic interest.
But wait. If you’re a fan of Jenny Han’s original books, the ages feel a bit different because of how the narrative stretches. In the show, we’re dealing with actors like Lola Tung and Gavin Casalegno who are clearly in their 20s. It creates this weird cognitive dissonance. You’re watching a 20-something actor play a 16-year-old, and your brain is trying to reconcile the emotional weight of their decisions with their supposed age.
The Core Trio: Belly, Conrad, and Jeremiah
Let’s break down the ages during that first iconic summer. Belly is 15. Jeremiah is 16. Conrad is 17, going on 18. This age gap is small, but at that stage of life, two years feels like a decade. Conrad being nearly 18 means he’s looking at college, looking at the "real world," while Belly is still worried about her debutante ball and high school drama.
Jeremiah sits in that middle ground. He’s 16. He’s the golden retriever friend who hasn’t quite felt the crushing weight of adulthood yet. In Season 1, his age reflects his personality—fun, carefree, and a bit naive. But by the time we hit Season 2, which covers the events of It’s Not Summer Without You, a year has passed.
Belly is 16. Jeremiah is 17. Conrad is 19 and struggling through his freshman year at Brown.
The shift is massive.
Being 19 in a college dorm is worlds away from being 16 at home with your mom. This is why the tension in the second season feels so much heavier. They aren't just kids in a beach house anymore; they are young adults dealing with grief, estate lawyers, and the terrifying realization that their childhood sanctuary is disappearing.
What about the "Time Jump" in Season 3?
If the show follows We’ll Always Have Summer (the third book), we are looking at a major leap. We’re talking about Belly being 18 or 19 and finishing her freshman year of college. Jeremiah is around 20. Conrad is 21.
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This is where the "how old are they" question gets controversial.
In the third book, there’s a marriage plot. People lose their minds over this. Why? Because 19 and 20 is young to be making those kinds of life-altering decisions. If you’re watching the show, you have to remember that while the actors look like adults, the characters are still technically teenagers or very young adults. Belly’s impulsivity makes a lot more sense when you remember she hasn't even hit her 21st birthday yet.
The Supporting Cast and the Parental Age Gap
We can't talk about the kids without mentioning Laurel and Susannah. Their ages aren't explicitly shouted from the rooftops, but we can do some math. They’ve been friends since college. Assuming they graduated around 22 and had kids a few years later, they are likely in their late 40s.
Then there’s Steven. Steven is the older brother, usually a year or two ahead of the rest. In the first season, he’s 17 and heading off to college. By Season 2, he’s 18, experiencing that weird "home for the summer" vibe where you feel like a guest in your own house.
Taylor, Belly’s best friend, is the same age as Belly. 15 in the beginning, 16 in the second act. She feels older, though. Taylor has that "older soul" energy—or maybe just more experience with high school social hierarchies.
- Belly Conklin: 15 (S1), 16 (S2), 18/19 (Expected S3)
- Conrad Fisher: 17 (S1), 18/19 (S2), 21 (Expected S3)
- Jeremiah Fisher: 16 (S1), 17 (S2), 20 (Expected S3)
- Steven Conklin: 17 (S1), 18 (S2)
- Taylor: 15 (S1), 16 (S2)
Why the ages actually matter for the plot
If Belly was 18 in Season 1, the show would be a completely different genre. The magic of The Summer I Turned Pretty is the "coming of age" aspect. It’s about that specific, fleeting moment where you stop being a child.
The age gap between Conrad and Belly is only two years, but when he’s at Brown and she’s still in high school, it might as well be a canyon. He’s reading existential philosophy and dealing with his mother’s illness in a dorm room; she’s worried about volleyball camp. That gap is the source of almost all their miscommunication. Conrad treats her like a kid because, by his college-aged standards, she is one.
Jeremiah, being closer in age, feels more like a peer. He’s there. He’s present. He isn't "away" at school yet in the same way. This is why the Team Jeremiah vs. Team Conrad debate often boils down to a preference for maturity levels.
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Real Life vs. Screen Life: The Actor Age Gap
It’s an open secret in Hollywood: actors are almost always older than their characters. This creates a bit of a "Dawson's Creek" effect where everyone looks remarkably polished for a 16-year-old.
Lola Tung was born in 2002. When Season 1 filmed, she was around 19 playing a 15-year-old. Not a huge stretch. Christopher Briney (Conrad) was born in 1998, making him about 23-24 during the first season. Gavin Casalegno (Jeremiah) was born in 1999.
This is why the romance scenes feel "TV-appropriate" but might feel a little intense if you strictly visualize a real-world 15-year-old. The show balances this by leaning into the emotional maturity of the characters rather than their literal birth dates.
The Psychology of 16
In many ways, how old are they in The Summer I Turned Pretty is the only question that matters for understanding the "Why did she do that?" moments.
Sixteen is an age of intense emotional stakes. Everything is the "first" or the "last." The heartbreak feels like the end of the world because, for a sixteen-year-old, it is the most pain they have ever felt. When Conrad ignores Belly’s texts, it isn't just a snub; it’s a soul-crushing rejection. When Jeremiah feels like the "spare," it’s tied to his developing identity as a young man.
If they were 25, we’d tell them to go to therapy and move on. Because they are teens, we let them have their drama.
The Evolution of the Timeline
One thing Jenny Han does brilliantly is tracking how these ages shift the family dynamics. In the first season, the parents still hold the power. They decide the dinners, the beach trips, the rules.
By the second season/book, the power shifts. The "kids" have to take charge. Conrad is trying to save the house. Belly is trying to save Conrad. Steven is trying to keep everyone sane. They are forced into adult roles before their ages really justify it.
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That’s the tragedy of the story. Susannah’s death forces them to grow up instantly. You go from being 16 and drinking Shirley Temples at the club to being 17 and discussing property taxes and grief.
Misconceptions about the Book Ages
A common mistake fans make is assuming the books and show are identical. They aren't. Han updated several elements for the screen to make them feel more contemporary. However, the foundational ages remained the same to preserve that "summer of change" feeling.
Some people think Conrad is much older because he’s so brooding. He’s not. He’s just a teenager who doesn't know how to process big emotions, so he shuts down. That’s a classic 18-year-old move. On the flip side, some think Jeremiah is younger because he’s bubbly. Nope. He’s the middle child of the group, usually just a year behind Conrad.
Final Perspective on the Cousins Beach Timeline
Understanding the ages of the characters helps navigate the messy love triangle without getting frustrated by their choices. They are young. They are making mistakes. They are learning how to be people.
If you’re watching the series for the first time or re-reading the trilogy, keep these milestones in mind:
- Season 1 is about the end of childhood (Age 15/16).
- Season 2 is about the harsh reality of the transition (Age 16/17).
- Season 3 will likely be about the definitive step into adulthood (Age 18-21).
To get the most out of the story, look at the specific year each character is in school. Steven's graduation is a huge marker for Season 1, just as Belly's college search becomes a focal point later. These aren't just background details; they are the anchors for the entire emotional arc.
Pay attention to the small mentions of "Freshman year" or "Senior year" in the dialogue. Those are the breadcrumbs Jenny Han leaves to make sure we know exactly where these characters stand on their journey to growing up. Whether you're Team Conrad or Team Jeremiah, their ages explain a lot more about their behavior than their personalities ever could.
Check the official Prime Video character bios if you ever get lost, as they occasionally update "official" ages to align with the show's specific calendar year. Most importantly, remember that in Cousins Beach, time seems to move a little slower, even if the kids are growing up faster than they'd like.