Two Teenagers Built a Calorie App in High School. Zach Yadegari was 17 years old. Sitting in a high school classroom. Building a startup.
Two years later he sold it for tens of millions of dollars. Then announced he’s dropping out of college to do it again.
This is the most motivating — and slightly intimidating — story in tech right now.
What Cal AI Actually Is
The problem Cal AI solved is one almost everyone who’s ever tried to lose weight knows personally.
You download a calorie tracking app on Monday with the best intentions. You log breakfast. You log lunch. By Wednesday you’ve given up because manually searching for every food, estimating portion sizes, and typing in ingredients feels like filing your taxes after every meal.
Zach Yadegari and his high school friend Henry Langmack looked at that friction and built the obvious solution. Take a photo of your food. AI figures out the calories. Done.
No manual entry. No database searching. No portion size guessing. Just point your camera at a plate of pasta and get your macros in three seconds.
The Numbers That Don’t Feel Real
Cal AI launched in 2024. In under two years it hit 15 million downloads. Revenue crossed $40 million annually. The founding team was seven people — including two teenagers doing homework between investor calls.
To put that in context — most venture-backed startups with professional CEOs, experienced teams, and millions in funding never reach those numbers. These two did it while attending school.
The growth didn’t come from traditional marketing. It came from TikTok and Instagram, where Gen Z users — who found every existing calorie app clunky and annoying — genuinely loved what Cal AI did and told everyone about it. The app spread the way things spread when they actually solve a real problem: person to person, recommendation by recommendation, because it worked better than the alternative.
Why MyFitnessPal Paid Up
MyFitnessPal has dominated calorie tracking for over a decade. More than 200 million registered users. A food database covering 20 million items. The most recognizable brand in nutrition apps by a mile.
It also watched Cal AI eat into its user base among younger users — the demographic that will define the health app market for the next twenty years — and decided buying was faster than building.
MyFitnessPal CEO Mike Fisher had been watching Cal AI climb app store rankings for over a year before closing the deal. After meeting Yadegari in person, his assessment was simple: “You have a conversation with them and you walk away saying this is an impressive young man.”
The deal keeps Cal AI running independently — same app, same experience — with one upgrade already live: access to MyFitnessPal’s enormous nutrition database. Cal AI users can now log with AI speed and verify against data covering 380 restaurant chains and 68,500 brands.
That’s a genuinely good outcome for users who were already happy with the product.
The Part That Should Actually Inspire You
This isn’t Yadegari’s first exit. At 16 he built and sold a website called Totally Science — an “unblocked” gaming site that let students play games around school internet filters. A business built specifically for the captive audience he was part of every day.
He saw a problem his classmates had. He built a solution. He sold it. Twice. Before turning 20.
His co-founder Henry Langmack isn’t planning on stopping either. Neither is Yadegari — who was previously on the record saying he wanted a normal college experience and didn’t want to be “an archetypal dropout founder.” That was last year. He’s now dropping out to build his next company.
Apparently $40 million has a way of clarifying your priorities.
What This Means for the Bigger Picture
As we covered when reporting on how AI agents are taking over enterprise software at Microsoft — the AI disruption isn’t happening only in boardrooms and data centers. It’s happening in high school classrooms.
The average age of breakthrough AI founders is falling. The tools that used to require engineering teams and years of experience are now accessible to anyone with curiosity and time. Speed, creativity, and willingness to actually ship something beat credentials and experience more often than the traditional startup world wants to admit.
Cal AI is proof of that. A photo-based calorie counter built by teenagers using AI tools available to anyone, distributed through social media they grew up on, solving a problem they understood from the inside because they lived it every day.
The incumbents spent years building elaborate nutrition databases. Two kids with phones beat them to the thing users actually wanted.
Also read: Meta Is Firing 16,000 People — And AI Is the Reason
Word count: ~580
Reading time: 3 min
Internal links:
- Microsoft AI Agents article — “Also read: Microsoft Wants to Charge You for AI Employees”
- Meta layoffs article — “Also read: Meta Is Firing 16,000 People”
External links:
- TechCrunch — original acquisition report
- Inc. — Zach Yadegari interview source