# Co-founder Equity Calculator

> Split startup equity between co-founders, see the 4-year vesting schedule with 1-year cliff, and simulate dilution from a future funding round. Free, in your browser, no upload.

URL: https://uttir.com/cofounder-equity
Categories: calculators, generators
Privacy: Your team and dilution numbers stay in your browser. Nothing is uploaded to a server.

## About

Add the co-founders, set each person's equity percentage, and see the vesting schedule laid out month by month. Optionally add a future funding round to see how the cap table changes after a SAFE or priced round.

The default is standard startup vesting: 4 years total, 1-year cliff, monthly thereafter. Adjust if your team has a different arrangement.

## How to use

1. **Add co-founders** — Name and equity percent. The split must add up to 100% for the calculator to work.
2. **Set the vesting terms** — Default: 4 years total, 1-year cliff, monthly. Adjust per founder if needed.
3. **Optionally add a funding round** — Pre-money, raise, and (for SAFEs) cap. The dilution simulator estimates post-money ownership.

## Examples

### Two co-founders, 50/50 split

The classic equal split. Both vest 4 years with a 1-year cliff, so neither can leave with half the company after 3 months.

Input:

```
Founder A: 50%, Founder B: 50%
```

Output:

```
Each founder vests 25% after year 1, then ~2% per month. Total vested at month 48: 100%.
```

### Three-person team, weighted split

The technical co-founder gets more, the part-timer gets less, the business co-founder is in the middle. Adjust until the team agrees.

Input:

```
Tech: 45%, Biz: 35%, Part-time: 20%
```

Output:

```
At a $5M pre-money, $1M raise, the cap table shifts: Tech 36%, Biz 28%, Part-time 16%, Investors 20%.
```

### Simulating a SAFE round

You have $200K from a SAFE at a $5M cap. A year later, you raise a $2M priced round at $10M pre. See the founder dilution.

Input:

```
SAFE $200K @ $5M cap + Priced round $2M @ $10M pre
```

Output:

```
SAFE converts at 4% of the cap table, priced round adds 20%, founders are diluted accordingly.
```

## FAQ

### Is my cap table uploaded?

No. The math runs in your browser. The names, equity percentages, vesting dates, and dilution numbers never leave the page.

### What vesting terms should I use?

The standard for US tech startups is 4 years total with a 1-year cliff, monthly vesting after the cliff. Some teams use 3 years, or 6-month cliffs, or no cliff. The calculator lets you change these per founder.

### What is a cliff?

The cliff is the minimum time a co-founder has to stay before any equity vests. With a 1-year cliff, a co-founder who leaves in month 6 walks away with 0%. At month 12, 25% vests in one tranche (1/4 of the total). After the cliff, the remaining equity vests monthly.

### How accurate is the dilution simulation?

It is a quick estimate. SAFE conversion uses a cap-only model (the SAFE converts at the lower of the cap price and the round price). For SAFEs with discounts, MFN clauses, or post-money SAFEs, the math is more complex. For a real cap table, use a dedicated tool.

### What is the "post-money valuation"?

Pre-money is the company value before the new investment. Post-money = pre-money + the amount raised. So a $5M pre-money with a $1M raise is a $6M post-money. The investor owns raise / post-money = 16.7% of the company after the round.

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For the full HTML page with the live tool, visit https://uttir.com/cofounder-equity.
This file is the markdown rendering at https://uttir.com/cofounder-equity.md. See https://uttir.com/llms.txt for a site-wide summary.