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.

Names

## Scores (0 to 10)

Idea and early vision

Full-time commitment

Cash put in

Skills the project needs

Customers or network brought

Risk taken (left a job, savings)

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](https://whoownswhat.xyz/tools/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](https://whoownswhat.xyz/tools/founder-agreement-template).
- Check who controls what with the [access audit](https://whoownswhat.xyz/tools/access-audit).

**Store the agreed shares in the app and let every founder confirm them with their own sign-in.**

[Start free in the app](https://whoownswhat.xyz/app)

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Source: https://whoownswhat.xyz/tools/equity-split-calculator
Agent index: https://whoownswhat.xyz/llms.txt