The Problem We Solve
Every year, thousands of founders negotiate equity deals without truly understanding the math. They accept term sheets without modeling dilution. They sign SAFE notes without knowing what they convert to. They run out of cash because they miscalculated their runway.
The existing tools are either enterprise cap table platforms that cost $100+/month (Carta, Pulley) or basic Excel templates that can't visualize what's happening. There's nothing in between for the individual founder who just needs to understand their equity.
Our Mission
FounderMath exists to give every founder — regardless of their math skills or budget — the ability to understand and visualize their equity situation. We believe the best founders make informed decisions, and informed decisions require clear, accurate numbers.
Clarity Over Complexity
Startup equity is complex by nature. Our job is to make it visual and intuitive, not to oversimplify or hide the math.
Founder-First
Every feature is designed for the individual founder's perspective — not investors, not lawyers, not enterprise HR departments.
Free to Start
Every calculator works for free. You should never have to pay to understand your own equity. Pro features are for power users who need more.
Open & Honest
No dark patterns, no hidden fees, no surprise charges. Our pricing is on the homepage and our math is transparent.
Our Story
The Frustration
We watched friends and fellow founders struggle with equity math — spending hours in spreadsheets, making mistakes that cost real money, and paying lawyers $500/hour to explain basic dilution concepts.
The Gap
Carta and Pulley serve companies managing cap tables. Free calculators are too basic. Nobody made a tool for the founder asking "what happens to MY equity if I raise a seed round?"
The Solution
FounderMath — six interactive calculators that turn confusing equity math into beautiful, real-time visualizations. Drag a slider, see your dilution. Add a round, understand the impact.
Today
We're building in public, shipping fast, and listening to founders. Every feature starts with a real question from a real founder.
What Founders Say
We're just getting started, but here's what early users tell us:
- "I finally understand what my SAFE converts to. This took 30 seconds instead of 3 hours in a spreadsheet."
- "The dilution simulator just saved me from accepting a bad term sheet."
- "I share this with every founder in my accelerator cohort."
Built With
FounderMath is a modern web application built with performance and simplicity in mind:
- Vanilla JavaScript — fast, no framework overhead
- Chart.js — interactive, responsive visualizations
- Client-side calculations — your data never leaves your browser
- Static hosting on Vercel — instant loading, $0 infrastructure cost
- Stripe — secure payment processing
Your financial data stays on your device. We never see your numbers, your cap table, or your scenarios. Privacy isn't a feature — it's the default.