Startup Equity Dilution & SAFE Note Simulator
Model co-founder dilution pools, pre-seed/seed SAFE note share conversions, employee option pools, and priced funding round valuations side-by-side.
shares
SAFEs: 11.5%
Series A: 17.0%
Options: 10.0%
| Shareholder Category | Calculated Shares | Ownership % |
|---|---|---|
| Original Founders Pool | 8,000,000 | 61.5% |
| SAFE Investors Conversion | 1,500,000 | 11.5% |
| Series A New Investors | 2,200,000 | 17.0% |
| Unallocated Option Pool (Post-Round) | 1,300,000 | 10.0% |
| Total Post-Round Shares Pool | 13,000,000 | 100.0% |
The Dynamics of Startup Equity Dilution
For startup founders, capital fundraising is a double-edged sword. While securing venture capital fuels business scaling and product expansion, selling shares dilutes early co-founders and employee ownership pools. Understanding how SAFEs (Simple Agreements for Future Equity), convertible debt notes, and priced rounds interact is critical to preserve long-term control. Our Startup Equity Dilution Simulator models these capitalization events in detail.
Understanding SAFE Note Conversion Mechanics
Originally introduced by Y Combinator, SAFEs are financial agreements that defer priced equity conversions to a future funding round. When a priced round (like a Series A) occurs, the SAFE converts into equity at the lower of two prices:
- Valuation Cap Price: The maximum valuation at which SAFE funds convert to shares, protecting early investors if the priced round pre-money valuation is high.
- Discount Price: A pre-negotiated percentage discount (typically 10% to 20%) off the priced round share price, rewarding early risk.
How the Employee Option Pool Dilutes Founders
Lead venture capital investors typically require a post-round unallocated option pool (e.g. 10% to 15%) to recruit future employees. Crucially, investors structure the term sheet so that this option pool is created **pre-money**, meaning its dilutive impact falls entirely on the founding team and converting SAFE holders, rather than the incoming priced round investors.
Strategies to Manage Equity Dilution
- Negotiate Post-Money Option Pools: Push for option pool expansions to occur post-money, spreading the dilution burden across both founders and incoming Series A investors.
- Model SAFE Conversions Early: Safe notes seem simple, but stacking multiple notes with different valuation caps can lead to massive surprise dilution. Model conversions before signing term sheets.