In brief
- At just 18 years old, Zach Yadegari is running a tech company projected to bring in $30 million this year.
- Yadegari started Cal AI after being rejected by the majority of colleges he applied to.
- Launched in 2023, Cal AI has been downloaded more than 5 million times combined on both iOS and Android.
At just 18 years old, Zach Yadegari is running a tech company projected to bring in $30 million this year—all while finishing his senior year of high school.
The Long Island teen is the founder of Cal AI, a nutrition and fitness app that uses artificial intelligence to analyze photos of meals and instantly estimate their calories and nutrients.
Alongside sleep, experts say the key to a longer, healthier life is regular exercise, avoiding smoking and excessive alcohol consumption, and maintaining a balanced diet.
However, tracking all of this can be tedious, as many apps require manual data entry. Now, a growing number of apps are using AI and smartphone cameras to make it easier.
Launched in 2023, Cal AI has been downloaded more than 5 million times combined on both iOS and Android. The company now employs a 17-person team.
Yadegari, who taught himself to code by watching YouTube videos starting at age 7, sold his first startup at 16.
“I think this balance and complementary feel between human and AI interaction, this is really where the future is headed,” Yadegari told Fox 5 New York.
Yadegari’s first company, Totally Science—a gaming platform that enabled students to access games at school by circumventing firewall restrictions—was sold for $100,000 in January 2024. At the time, it had more than 5 million users.
“At a young age, I saw that kids were funneled down the same narrow path: get good grades, attend a good college, land a good job, live a good life,” Yadegari wrote in a post on X. “It felt like a prescriptive formula, devoid of individuality. I rejected convention and took to self-learning.”
Despite maintaining a 4.0 GPA and scoring 34 on the ACT, Yadegari said he was rejected by most of the colleges to which he applied.
“I wanted to help cultivate a community, so I guess it is their loss,” he said. “I’ll do that somewhere else.”
Now it appears Yadegari is having the last laugh with one of the top health and fitness apps on the Apple and Google Play Stores.
How Cal AI Works
Cal AI allows users to take photos of their meals, using AI to estimate calorie counts and identify ingredients and nutrients, including protein, carbohydrates, and fats. It also includes a Health Score that evaluates the food’s nutritional value.
Beyond meal tracking, Cal AI functions as a fitness tracker. Users can log workout details, and using generative AI, the app estimates calories burned and updates daily totals.
In addition to its user-friendly interface, Cal AI’s $30 annual subscription gives it a competitive edge in a crowded marketplace.
Indeed, Cal AI is among a growing number of AI-powered fitness and calorie-tracking apps. Others include SnapCalorie, ParrotPal, Dr. Cal, and Calorie Deficit Tracker.
For those hesitant to download another app, AI models like OpenAI’s ChatGPT, Anthropic’s Claude, and Google’s Gemini can also provide insights into food and exercise.

However, because such models don’t retain memory across sessions, their long-term use for tracking progress may be limited.
As for Yadegari, with millions of downloads and millions in revenue, he remains determined to pursue higher education.
“We are all individuals, but we are also part of something larger,” he wrote. “Through college, I will contribute to and grow within that large whole, empowering me to leave an even greater lasting, positive impact on the world.”
Edited by Sebastian Sinclair