How do you split equity fairly?
Rate what each founder brings and get a reasoned proposal for your split, with notes on vesting, part-time work and money paid in.
- About 5 minutes
- No sign-up
- Nothing stored
Your proposal
- Lena58%
- Jonas42%
Rounded to whole percent. A starting point for your conversation, not a verdict.
Where your shares come from
What each factor gives each founder, in percent of the split. Rounded so that every row and the total add up exactly.
- Time and commitment30%Lena: 18.7%Jonas: 11.3%
- Role and responsibility20%Lena: 10.0%Jonas: 10.0%
- Skills and experience15%Lena: 5.6%Jonas: 9.4%
- Network and access10%Lena: 7.1%Jonas: 2.9%
- Prior work and idea10%Lena: 6.7%Jonas: 3.3%
- Risk and sacrifice15%Lena: 9.4%Jonas: 5.6%
TotalLena: 57.6%Jonas: 42.4%
Watch out for
- Jonas gives less time (3 of 5). Agree when full-time starts and whether the split changes then.
- Lena pays in €20,000. Handle it separately, not through the split.Founder agreement
- Vesting for everyone: four years with a one-year cliff. It keeps the split fair if someone leaves.More on vesting
How the calculator works
Every factor has a weight from 1 to 10, which sets its share of the split: with the default weights, time and commitment gets 6 of 20 points, that is 30 %. Within a factor, that share is split by your points: if you both give a 5, you share it equally; at 5 to 3, the first founder gets five eighths of it. A 0 gets nothing of that factor. The sum over all factors is the proposal.
The method follows our guide to splitting equity: each founder rates alone first, then you compare. Where your ratings lie far apart is the real topic of your conversation.
Time and commitment
How much time each founder gives, from when and how firmly. It weighs most, because years of execution build the company.
Default weight 6 of 10, that is 30%
Role and responsibility
Who leads the company, sells or owns the product, and answers for it.
Default weight 4 of 10, that is 20%
Skills and experience
Know-how and experience that are hard to replace and make the start-up faster.
Default weight 3 of 10, that is 15%
Network and access
Contacts that open doors: to customers, partners, talent or money.
Default weight 2 of 10, that is 10%
Prior work and idea
What existed before the start. It counts on purpose for little: an idea without execution is worth little.
Default weight 2 of 10, that is 10%
Risk and sacrifice
What each founder gives up or puts at stake personally: a salary, a permanent job, a personal guarantee. Money paid in does not count here but separately, as a loan or as paid-for shares.
Default weight 3 of 10, that is 15%
What the calculator leaves out
- Money paid in: it sits next to the split, as a loan or as paid-for shares.
- Option pool and funding rounds: the cap table calculator shows how your shares dilute.
- Vesting, leaver rules and the legal form: they belong in your founder agreement.
- Tax and valuation: have your tax advisor check them.
Questions about the equity split calculator
Is a 50/50 split wrong?
No, if it comes out of an honest rating. The problem is an equal split as a reflex, without talking about time, role and risk. Two founders at 50/50 also need a rule for deadlocks in their founder agreement.
How much is the idea worth?
Less than most people think. An idea without years of execution is worth little, so prior work and the idea get a weight of 2 by default, which is 10 % of the split. A large premium for the idea often turns into a dispute once the work starts.
What if a co-founder joins later?
Whoever joins after the first customers carries less early risk and usually gets less. Rate that person by what they bring from now on, and let their vesting start when they join.
Should we take the result exactly?
Take it as a starting point. Whether it says 58 to 42 or 60 to 40 matters less than the reasons behind it. Settle on a figure that feels fair to everyone and write it into your founder agreement.
Do you store what we enter?
No. The calculator runs in your browser and sends nothing to Cofoundista. When you continue in the cap table calculator, the split travels in the address after the # sign, which browsers never send to a server.
Ready for the next step?
Publish a co-founder search, or join a start-up as a co-founder.