Equity Split Calculator
Free equity split calculator for co-founders. Score contributions across 6 factors — idea, time, skills, capital, risk, and network — with customizable weights. See your fair split instantly. No sign-up required.
Number of Co-Founders
How to Calculate Your Equity Split
1. Set the Number of Co-Founders
Choose between 2 and 5 cofounders. Each person gets their own scoring card where you can enter a name and rate their contributions.
2. Score Each Founder's Contributions
Rate each cofounder from 0-10 across six factors: Idea & IP (who came up with it), Time Commitment (full-time vs part-time), Technical Skills (how hard to replace), Capital Invested (money in), Risk & Sacrifice (opportunity cost), and Network (investor and customer access).
3. Customize Factor Weights (Optional)
Toggle advanced mode to adjust how much each factor matters. Time and skills default to 1.5x because they represent ongoing value. Network defaults to 0.5x since connections depreciate. Adjust these based on your startup's specific needs.
4. Review Your Equity Split
See each cofounder's percentage visualized as a pie chart, with a comparison to an equal split. The calculator also provides vesting recommendations and flags potential imbalances if one founder's share differs significantly from the others.
Key Equity Terms
- Equity Split
- The division of company ownership among cofounders, expressed as percentages. A 60/40 split means one founder owns 60% and the other 40%. The split determines voting power, dividend rights, and payout at exit.
- Vesting Schedule
- A timeline over which equity is earned. The standard is 4 years with a 1-year cliff: no equity vests in year one, 25% vests at month 12, then the remainder vests monthly. Protects against early departures.
- Cliff Period
- The initial period (usually 12 months) before any equity vests. If a cofounder leaves before the cliff, they receive nothing. After the cliff, a lump sum (typically 25%) vests immediately.
- Cap Table
- Short for capitalization table — a record of who owns what percentage of the company. Includes founders, investors, and employee option pools. A clean cap table is essential for fundraising.
- Slicing Pie
- A dynamic equity framework by Mike Moyer where each person's share always equals their proportion of total at-risk contributions. Unlike fixed splits, equity adjusts continuously until a freeze event like funding.
Tips for a Fair Equity Split
- 1.Have the equity conversation early — 73% of teams split within the first month (Wasserman, HBS). The longer you wait, the harder it gets.
- 2.Score independently first, then compare. Gaps between self-assessment and peer assessment reveal where you disagree and need to negotiate.
- 3.Always implement vesting — even among best friends. 23% of cofounders leave within 3 years. Vesting protects everyone.
- 4.Don't give single-digit equity to a cofounder. If their contribution only justifies 5%, they should be an advisor with a standard 0.5-1% advisor grant instead.
- 5.Revisit your cap table before major events: new cofounders, fundraising, pivots, or significant role changes.
- 6.Get a lawyer to formalize the agreement. Template documents miss edge cases. Budget $2,000-$5,000 for a startup attorney.
Frequently Asked Questions
A fair split reflects each cofounder's contribution across idea, time, skills, capital, risk, and network. Carta data shows the median two-founder split is 51/49 as of 2024. Equal splits work when contributions are genuinely comparable, but weighted splits better reflect different levels of commitment and risk.
Not necessarily. Equal splits are common (45.9% of two-person teams) but Harvard Business School research shows teams that default to 50-50 without discussion are more likely to face conflict later. The key is having a structured conversation about each person's contributions before deciding.
Vesting means equity is earned over time — typically 4 years with a 1-year cliff. If a cofounder leaves before the cliff, they forfeit all equity. After the cliff, 25% vests, then the rest monthly. This protects against cofounders leaving early with unearned equity. 23% of cofounders leave within 3 years.
Each factor (idea, time, skills, capital, risk, network) is scored 0-10 per founder and multiplied by a weight. Higher weights mean that factor matters more. Time and skills default to 1.5x weight because they represent ongoing value, while network defaults to 0.5x since it depreciates over time.
Yes. Toggle "Customize factor weights" to adjust each factor's importance from 0.5x to 3.0x. For example, in a deep-tech startup you might increase the skills weight to 2.5x, while for a sales-driven business you might boost network to 1.5x.
The calculator supports 2-5 cofounders. The same weighted scoring applies — each person's equity percentage equals their weighted score divided by the total. For three-person teams, Carta data shows equal splits rose from 12.1% to 26.9% between 2015 and 2024.
No. All calculations happen entirely in your browser. No data is sent to any server, stored, or shared. Your equity discussion stays completely private.
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Cap Table
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