🛠️ Tool
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Free
Beginner
A free, no-signup calculator that forces you and your co-founder to actually weigh the inputs (idea, roles, who is full time, who is CEO, capital) instead of defaulting to a lazy 50/50. Everything stays on your device, so it is a safe way to run the numbers together in one sitting. Treat its output as a conversation starter for negotiating your split, not a final verdict.
Foundrs Co-Founder Equity Calculator
From Foundrs by Foundrs ~10 minutes to work through
- It turns a vague argument into a structured one: you assign weight to contributions and it hands back a percentage you can then discuss and adjust.
- It deliberately pushes back on reflexive 50/50 splits, which is useful when one of you is full time and the other is not.
- Know its limits: it assumes a 4 year vest with no cliff and does not model salaries or later cash investment, so pair it with a real vesting agreement.
