Free Cofounder Equity Split Calculator

Splitting equity equally is rarely fair. Weigh each founder's time commitment, capital, idea, expertise, responsibilities, and risk to reach a split you can both defend — free and private, nothing leaves your browser.

Factor
Time commitment
Full-time vs part-time, and opportunity cost of the time given.
Weight: 25
Capital invested
Cash or equivalent each founder puts into the company.
Weight: 20
Idea & IP
Who originated the idea and contributes core intellectual property.
Weight: 15
Expertise & skills
Domain knowledge and skills critical to building the product.
Weight: 15
Responsibilities
Scope of the role and ongoing operational ownership.
Weight: 15
Risk taken
Personal and financial risk, e.g. leaving a stable job first.
Weight: 10

Suggested equity split

Score each founder 0-10 per factor. Percentages update live and always total 100%.

Founder 150%
Founder 250%

How the calculation works

Each founder rates themselves 0-10 on six weighted contribution factors. For every factor, your share is your score divided by the founders' total, multiplied by the factor's weight. The results are normalized so they always add up to 100%.

Use it as a structured starting point for the conversation, not a verdict. The hardest part of a split is agreeing on the inputs.

Before you split equity

Equity is a 5-10 year commitment. Make sure you actually work well together first: test your cofounder compatibility across 8 startup-specific dimensions, then lock the terms in a written agreement.

Disclaimer

This calculator is for informational purposes only and does not constitute legal, financial, or tax advice. Equity decisions should be reviewed with a qualified professional and formalized in a proper agreement.

Free Cofounder Equity Split Calculator | CofounderFit