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Calculators/Co-Founder Equity
Takes about 3 minutesFree, no sign-upWeighted & fair

Co-Founder Equity Calculator

Splitting equity is one of the hardest early conversations. This calculator turns it into a fair, structured one. Rate each founder across the factors that really matter, and get a defensible split you can all stand behind.

Your inputsRate each founder from 0 to 10 on every factor
Factor
Importance
Idea & vision
Who conceived it and shapes direction
You
Co-founder
Capital invested
Money put into the business
You
Co-founder
Time & commitment
Full-time effort and hours
You
Co-founder
Skills & execution
Ability to actually build it
You
Co-founder
Network & relationships
Customers, hires, investors
You
Co-founder
Risk taken
Salary given up, opportunity cost
You
Co-founder
Suggested equity split
Near even
You
53.8%
Co-founder
46.2%
Largest share
53.8%
Split spread
8 pts
vs equal split
+3.8%
Suggested vesting
4 yr, 1 yr cliff
Equity distribution
The suggested ownership split
You54%
Co-founder46%
Contribution profiles
How each founder scores across factors
You
Co-founder
Weighted contribution score
The totals behind the split
You98 pts
Co-founder84 pts
This is a structured starting point for a human conversation, not a verdict. The fairest split is the one all founders understand and agree to. Always put the final agreement in writing with vesting, and have a lawyer review it.
How this calculator works

The weighted equity formula

Each founder's weighted score (factor weight × rating) summed across all factors becomes their share of the total equity.

The formulas
Founder scoreSum of (Factor weight × Rating)
Total scoreSum of all founder scores
Equity shareFounder score ÷ Total score
Every field explained

What each input actually means

Idea & vision
Who originated the concept and continues to shape where the company is heading. Worth something, but rarely the biggest factor.
Capital invested
Money each founder has personally put into the business. Real cash at risk usually deserves real weight.
Time & commitment
Whether a founder is full-time and how much they truly put in. Often the single most important factor early on.
Skills & execution
The ability to actually build the product, sell it and run the company day to day. Execution is what creates value.
Network & relationships
Access to customers, talent, partners and investors that meaningfully moves the company forward.
Risk taken
What each founder gave up to be here, such as a salary, another job or financial security. A fair split honours risk.
Benchmarks

Equity norms worth knowing

A few widely accepted conventions that keep founder equity healthy.

Always use vesting

A four year vest with a one year cliff is the standard. Nobody keeps meaningful equity if they leave in the first year.

Beware the perfectly equal split

Equal can be right, but choosing it to avoid an awkward talk often stores up resentment for later.

Value future contribution

Equity rewards the next few years of work, not just who showed up first. Weight commitment heavily.

Put it in writing

Whatever you agree, document it with a founder agreement and proper vesting, reviewed by a lawyer.

Questions, answered

Co-founder equity FAQ

Keep going

Your next move

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