Manuel Castro net worth
Quick answer
Manuel Castro's estimated net worth is $6.67M (range $4.67M – $10.0M) as of 2026. Manuel Castro is Founder at Napkin Math. Napkin Math valuation.
Manuel Castro is Founder at Napkin Math (YC P26). Independent Entrepreneurial Check model estimate from public YC data.
At a glance
- Company status: Active
- Education: Stanford University
- Region: United States of America
- Industries: Consumer
- Team size: 3
- Website: https://napkinmath.club
Who is Manuel Castro?
Manuel Castro is a Y Combinator founder known for his work with Napkin Math, a platform that provides resources for startups.
Highlights:
- Stanford University
- Sequoia Capital
- TechCrunch Disrupt
About Napkin Math
Napkin Math is the personalized AI food journal that people love to use. We gamify nutrition tracking so people are 2x more likely to stick with us than other trackers. Claire, Manuel, and I (best friends for 10 years from MIT) are obsessed with how we can make nutrition fun, and turn fun into health outcomes.
=== Existing consumer health apps focus on scaling a one-size-fits-all solution: calorie deficits. But...
FAQ: Manuel Castro net worth and Napkin Math valuation
What is Manuel Castro's net worth?
Manuel Castro's estimated net worth is $6.67M (range $4.67M – $10.0M) as of 2026. Manuel Castro is Founder at Napkin Math. Entrepreneurial Check publishes an independent model-based estimate from public company and role data. Not verified net worth, and Entrepreneurial Check is not affiliated with Y Combinator or the profiled companies.
What is Napkin Math valuation?
Napkin Math's estimated valuation on Entrepreneurial Check is $20.0M. That valuation, or a disclosed round when one is public, is the source for the paper-wealth estimate. Independent model output — not a verified appraisal or official mark.
What is Manuel Castro's role?
Manuel Castro is Founder at Napkin Math, a Y Combinator-backed startup (batch P26).