Equity Split Calculator

Calculate fair co-founder equity based on each person's contributions

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Co-Founder Equity Calculator

Calculate fair equity splits based on each founder's contributions. Rate each factor from 0-10 for each co-founder.

Co-Founders (2)

Contributions: Founder 1

Idea & IP5/10
NoneAverageExceptional

Original concept, patents, proprietary technology, or unique market insight that forms the foundation of the venture

Capital Investment5/10
NoneAverageExceptional

Cash invested into the company relative to other founders - includes personal funds, loans, or pre-seed capital

Time Commitment5/10
NoneAverageExceptional

Full-time vs part-time dedication - hours per week and duration committed to the venture

Domain Expertise5/10
NoneAverageExceptional

Industry knowledge, technical skills, and years of relevant experience that directly applies to building this business

Network & Connections5/10
NoneAverageExceptional

Access to potential customers, investors, advisors, partners, and talent that can accelerate growth

Risk Taken5/10
NoneAverageExceptional

Salary sacrifice, opportunity cost, personal guarantees, leaving a secure position, or other financial risk

Vesting Schedule

Suggested Equity Split

50/50
Founder 150.0%
Founder 250.0%

Pattern Comparison

Your split closely matches the "Equal Split" pattern. This is a well-established approach used by many successful startups.

Equal Split50/50

True partnership with equal ownership - works when contributions are genuinely balanced

Vesting Timeline

Standard: 4-year vesting with 12-month cliff. 25% vests at cliff.

Founder 150.0% total
At cliff:12.5%
Monthly:1.04%
Full vest:4 yrs
Founder 250.0% total
At cliff:12.5%
Monthly:1.04%
Full vest:4 yrs

Consider These Points

  • • All contributions are rated identically at 5/10. Consider discussing specific strengths and differences each founder brings.

Ready to formalize your partnership?

Learn about building effective co-founder relationships.

Read the Team Building Playbook

Understanding Founder Equity

Why Equity Conversations Matter

Equity splits are one of the most important decisions co-founders make. A poorly structured split can lead to resentment, disputes, and even company failure. Having explicit, data-driven conversations early prevents these problems.

The Contribution-Based Approach

Rather than defaulting to equal splits or arbitrary numbers, this calculator uses a contribution-based methodology. Each founder rates their contributions across six key factors, and the calculator suggests a proportional equity split.

Understanding the Factors

  • Idea & IP (15%): Who originated the concept? Do they bring patents, proprietary technology, or unique market insight? Note: Ideas alone are worth less than execution.
  • Capital Investment (20%):Cash invested matters, especially at early stages. This includes personal funds, loans you've secured, or pre-seed capital you've raised.
  • Time Commitment (25%): The highest-weighted factor. Full-time commitment is fundamentally different from part-time. Consider hours per week and duration committed.
  • Domain Expertise (15%): Deep industry knowledge or technical skills that directly apply to building the business. Years of relevant experience matter here.
  • Network & Connections (10%): Access to potential customers, investors, advisors, or talent. This is about who you can bring to the table.
  • Risk Taken (15%): What are you giving up? Salary sacrifice, opportunity cost, leaving a secure position, or personal financial risk all factor in.

Common Equity Patterns

There's no single "right" split, but some patterns are more common:

  • Equal Split (50/50): Works when contributions are genuinely balanced. Common among friends starting together with similar commitment levels.
  • Lead Founder (60/40): When one founder originated the idea, has more experience, or is taking on the CEO role.
  • Dominant Founder (70/30): When one founder brings significantly more—full-time vs part-time, capital investment, or critical expertise.

Why Vesting Protects Everyone

Vesting ensures that equity is earned over time, not given away upfront. The standard 4-year vesting with 1-year cliff means:

  • 1-Year Cliff: No equity vests until 12 months. If someone leaves before then, they get nothing.
  • Monthly Vesting: After the cliff, equity vests monthly over the remaining 3 years.
  • Full Vest at 4 Years: 100% of allocated equity is earned after 4 years.

This protects against "founder divorce"—if someone leaves early, they don't walk away with a large chunk of the company.

Best Practices

  • Have the conversation early: Before writing any code or raising any money.
  • Be explicit about contributions: Use this calculator to make the implicit explicit.
  • Document everything:Get a proper founders' agreement drafted by a startup lawyer.
  • Include vesting: Always. No exceptions.
  • Plan for change: Consider what happens if roles change, someone goes part-time, or new founders join.

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