Co-Founder Equity Split Calculator

Model a fair ownership split based on contributions. Includes vesting preview and fairness check.

Founder 1

Percentages are relative weights — they do not need to total 100.

After 1-year cliff: 0.0%

Founder 2

After 1-year cliff: 0.0%

Founder 3 (optional)

After 1-year cliff: 0.0%

Updates instantly as you type

Founder 1

33.0%

Founder 1

After 1-year cliff: 0.0%

Founder 2

33.0%

Founder 2

After 1-year cliff: 0.0%

Founder 3

0.0%

(optional)

After 1-year cliff: 0.0%

Equity Distribution 100%

Blue: Founder 1 · Indigo: Founder 2 · Purple: Founder 3

Illustrative only. Equity splits are always subjective and should be discussed with co-founders and legal counsel.

How to Split Equity Fairly

Equity splits are one of the most emotional and important early decisions in a startup. There is no perfect formula, but a weighted contribution model can help start the conversation objectively.

Common Weighting Factors

Vesting Basics

Standard founder vesting is 4 years with a 1-year cliff. This protects everyone if someone leaves early. Use the vesting preview to see how ownership evolves over time.

Important Reminder

This calculator is a starting point for discussion, not legal advice. Equity splits should always be formalized with a co-founder agreement and vesting schedule reviewed by a startup attorney.

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