Cofounder equity split calculator

How this is calculated

Each of you gets points for five things, and your share is your points out of everyone's.

• Time ahead: the hours a week each of you will put in over the next year. Full time, 40 hours or more, rates 10, and 20 hours rate 5.
• Money: what each of you puts into the company. An amount has no scale next to hours and ratings, so it's rated against the most any of you puts in: the most rates 10, and half of it 5. So the currency never changes the split.
• The idea and the work so far, rated from 0 to 10.
• Role and responsibility, rated from 0 to 10: who runs what, and who answers for it.
• Skills and contacts that are hard to replace, rated from 0 to 10.

Each thing has a weight from 0 to 10, and your points for it are its weight times your rating. With a weight of 10, full time gives 100 points and 10 hours a week give 25. Your share is your points out of all the points. If you keep a share for people who join later, the rest is split this way.

Our weights lean on the work ahead: time 10, the role 7, skills and contacts 6, money 5 and the idea 4. Y Combinator argues that nearly all the work that makes a company is still ahead of you on the day you split it, which is why it favors an equal or nearly equal split. So the equal split sits beside yours, and the result says when yours is within 5 points of it.

The method is Frank Demmler's Founders' Pie Calculator, from Carnegie Mellon: weigh each factor, rate each person on it from 0 to 10, multiply and add it up. Hours and money are put on that scale as above. Both sources were read on 10 October 2026.

Shares are rounded to a tenth of a percent, and they always add up to the whole.

What it doesn't know

• Vesting. A share is usually earned over time, often four years with a one year cliff, so someone who leaves early keeps only part of it. The calculator splits what you agree today and doesn't model that.
• Money that's a loan. If someone's money is to be paid back rather than turned into a share, leave it out of their money field and write the loan down on its own.
• Small sums. Money is rated against the most any of you puts in, so a small sum next to nothing gets the whole money weight, as a large one would. If the money is small next to the work, leave it out or lower its weight.
• Company law and tax. How shares are issued, taxed and registered depends on the country. Ask a lawyer or an accountant where you register. Do you need a company to run a crowdfunding campaign? covers whether you need one at all.
• People who join later. First employees and advisers usually get shares from a reserve. Keep one with the field above, or agree it later.
• Your names. Names stay on this page and never go in the link, so a shared link opens with each cofounder numbered.

Questions

How should cofounders split equity?

By what each of you will bring from here on, more than by who had the idea. Agree the factors that matter for your company, rate each of you honestly and talk the result through. Many teams end up close to equal, and that's often a good sign.

Is a 50/50 split a good idea?

Often, when both of you will work full time and take similar risks, because it keeps you both committed. It also needs a way to break a tie, so agree who decides what before you disagree.

What is vesting, and do cofounders need it?

Vesting means each person earns their share over time instead of owning it all on day one. A common setup is four years with a one year cliff: leave before the first year is out and you keep nothing; at one year a quarter is yours, and the rest builds up month by month. It protects everyone if someone leaves early.

Do backers on CoFunders get equity?

No. Backers get the reward you promise, never a share of your company, so it stays yours and your cofounders'. What backing a campaign is, and what it isn't explains the difference.