Free calculator
Startup equity calculator for co-founders
Score each founder from 0 to 10 on six factors. Commitment counts most. You get a starting split to talk about, not a verdict.
Not legal or tax advice. Equity rules differ by country. Use the result to start the conversation, then write it down.
Scores (0 to 10)
Weights: full-time commitment 3, cash and skills 2 each, idea, network and risk 1 each. The cost of the first months is easy to track with the cost split calculator.
Do it with AI
Argue the split out with an AI first
Let an AI play devil's advocate for each founder before you sit down together.
We are [2 or 3] co-founders of [PROJECT]. Here is what each of us brings: [FOR EACH PERSON: role, hours per week, cash put in, key skills, network, risks taken]. Act as a neutral startup advisor, not a lawyer. 1) Propose three possible equity splits and explain the reasoning for each. 2) Argue the strongest case each founder could make for a bigger share. 3) Suggest a vesting schedule with a cliff and what happens to shares if someone leaves. 4) List the questions we should answer before we sign. Be direct about weaknesses in each position.
Why not just split it equally?
Equal splits are quick and avoid an awkward talk, but they ignore the person who goes full-time while the other keeps a job. Whatever you pick, add vesting so shares are earned over time, and write it down.
Frequently asked questions
How do co-founders split equity fairly?
Look at commitment, cash, skills, network and risk, give the most weight to full-time commitment, and add vesting so shares are earned over time.
What is vesting?
Shares are earned over a period, often four years with a one-year cliff. If someone leaves early, they keep only what has vested.
Is this calculator legal advice?
No. It gives a starting point for the conversation. Have a lawyer check the final agreement.
Next
- Write the result into the founders agreement.
- Check who controls what with the access audit.
Store the agreed shares in the app and let every founder confirm them with their own sign-in.