Startup Equity Split Calculator
Suggests an equity split among co-founders based on weighted contributions such as idea, capital, time commitment, and existing assets brought to the company.
Startup Co-Founder Equity Agreement
| Co-Founder | Cash Seed ($) | Commitment | Idea / IP | Equity Share |
|---|
- 4-Year Vesting: Equity vests proportionally on a monthly basis over 48 calendar months.
- 1-Year Cliff: 25% of total shares vest on the exact 12-month anniversary; 0% vests if departure occurs prior to 1 year.
- Accelerated Vesting: Double-trigger acceleration upon change of control / acquisition if involuntarily terminated.
Legal Notice: This document is generated for consensus-building and planning purposes. It does not constitute formal legal counsel. Official equity issuances must be memorialized in a formal Restricted Stock Purchase Agreement (RSPA) approved by your corporate attorney.
How to Use This Tool
- 1 Add or remove co-founders to match your founding team.
- 2 Assign individual scores for Capital Contributed, Full/Part-Time Commitment, Idea Origination, and Existing IP/Audience Assets.
- 3 Adjust the global weight sliders to reflect what your venture values most (e.g. execution time vs. upfront seed capital).
- 4 Inspect the computed equity percentage breakdown and visual bar allocation chart.
- 5 Click "Print & Save PDF" to export a clean, printable term sheet with vesting rules and signature lines.
Avoiding the Fatal 50/50 Handshake Trap
Equity splits between co-founders cause more damage after the fact than almost any other early decision, usually because the split was decided quickly and informally, often at a round number like 50 50, without weighing what each person actually brought to the table.
Capital, full time commitment versus part time, the original idea, and any existing assets like an audience or a codebase brought in from before the company started are the factors that most equity split frameworks weigh, though they rarely weigh them the same way twice.
This tool lets you assign relative importance to each factor and see a resulting split, which is meant to open a conversation between co-founders rather than settle it. The output is a starting point for negotiation, not a legal document, and any final split should still go through a lawyer and a proper vesting schedule regardless of what a calculator suggests.