Calculate Your Equity Split
Rate each co-founder on a scale of 0-10 for each dimension. The calculator will compute a weighted equity split based on relative contributions. Be honest -- this tool works best when all co-founders fill it out independently and compare results.
| DIMENSION | FOUNDER 1 | FOUNDER 2 |
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How the Methodology Works
This calculator uses a weighted contribution model. Each of the 7 dimensions is scored on a 0-10 scale for each co-founder. The dimensions are weighted differently because not all contributions are equal in building a startup:
Idea origination (weight: 5%). Ideas are important but overvalued. Execution matters 100x more. Having the original idea earns credit, but not as much as most idea-havers think.
Time commitment (weight: 25%). The most important factor. A co-founder working full-time, forgoing salary, and dedicating 60+ hours per week is contributing far more than someone working evenings and weekends. Score 10 for full-time, all-in. Score 3-5 for part-time.
Capital invested (weight: 15%). Money talks. A co-founder who puts in $50,000 of their savings is taking real financial risk. Score relative to total capital needs and each person's financial sacrifice.
Domain expertise (weight: 15%). Deep knowledge of the target market, industry connections, and understanding of customer pain points. This is what separates a co-founder from a hired contractor.
Technical skills (weight: 15%). Can they build the product? A technical co-founder who can ship the MVP without hiring anyone brings enormous value. Score 0 if they can't code, 10 if they're the primary builder.
Business/sales skills (weight: 15%). Can they sell the product, raise funding, form partnerships, and build the go-to-market strategy? A co-founder who can close deals and get the first 10 customers is invaluable.
Risk taken (weight: 10%). What is each person sacrificing? Quitting a $200K job to work on a startup for no salary is a 10. Keeping their day job and contributing on weekends is a 2-3. This accounts for opportunity cost.
Why Vesting Matters More Than the Split
Even a perfectly calculated equity split is useless without vesting. Vesting protects everyone by ensuring equity is earned over time through continued contribution. The industry standard is:
4-year vesting, 1-year cliff. No equity vests during the first year. At the 1-year mark, 25% vests at once. After that, equity vests monthly (1/48th per month) over the remaining 3 years. If a co-founder leaves after 6 months, they get nothing. After 18 months, they keep roughly 37.5%.
Without vesting, a co-founder could take 50% of the company and leave after three months. We've seen this destroy startups in Miami, New York, and everywhere else. Don't let it happen to yours. Every founder agreement should include vesting terms.
For more on structuring your co-founder agreement, read our Co-Founder Agreement Template.
Common Equity Split Mistakes
Splitting too early. Don't split equity on day one over coffee. Work together for 2-4 weeks first. See how each person actually performs, not how they promise to perform.
Equal splits by default. 50/50 feels fair but often isn't. If one founder is full-time and the other is part-time, 50/50 creates resentment. Use a framework like this calculator to arrive at an honest number.
No vesting. The single most common and most devastating mistake. Always vest. No exceptions.
Ignoring the conversation. Many co-founders avoid the equity conversation because it's uncomfortable. This guarantees a bigger, uglier fight later. Have the conversation early, use data (like this calculator), and put it in writing.
Not accounting for future contributions. Equity should reflect expected future contributions, not just past ones. A co-founder who will work full-time for the next 4 years matters more than one who contributed the initial idea but plans to stay part-time.