How to Split Equity Fairly with a Co-Founder
Struggling with co-founder equity? Learn how to calculate fair contributions, avoid the 50/50 trap, and set up dynamic vesting schedules.
Splitting equity is one of the earliest and most consequential conversations between co-founders. A bad equity split breeds resentment that destroys otherwise promising startups. This guide teaches you how to evaluate past contributions vs future commitment and establish rock-solid vesting schedules.
Step 1: The Idea is Worth 1% — Value Future Execution Over Past Brainstorms
A common founder mistake is giving 30% extra equity to whichever partner came up with the original idea in the shower. Ideas are worthless without years of operational grind.
Value the next 4 to 7 years of full-time sweat, sales execution, technical architecture, and fundraising over initial inspiration.
Step 2: Mandatory 4-Year Vesting with a 1-Year Cliff
Never grant 100% upfront equity without vesting. If a co-founder departs after 4 months due to personal reasons, they should not retain 50% of your company cap table while you grind for the next 5 years.
A standard 4-year vesting schedule with a 1-year cliff ensures equity is earned through sustained execution.
Step 3: Evaluate Capital vs Time Contributions
If one co-founder contributes $50,000 in early seed cash while the other draws zero salary, treat early cash as a convertible note or assign a fair seed-stage valuation rather than distorting common equity splits.