Startup Equity % Calculator
Calculate your current ownership percentage and model dilution through future funding rounds.
| Round | Investment | Pre-Money Val. | Post-Money Val. | Total Shares | Your Ownership | Dilution |
|---|
Understanding Startup Equity
Fully diluted shares include all outstanding common shares, preferred shares, options (both vested and unvested), warrants, and any other convertible securities. Always use fully diluted shares when calculating ownership — the difference can be significant.
Dilution occurs when a company issues new shares in a funding round. Your share count stays the same, but the total goes up, reducing your percentage. This is normal and expected — a smaller percentage of a more valuable company is usually better.
Option pool shuffle: Investors often require a new option pool (10–20% of post-money shares) to be created before their investment, using pre-money shares. This dilutes founders before the round, not after. Always clarify whether the option pool expansion happens pre- or post-money.
Formula: New shares issued = investment ÷ (pre-money valuation ÷ pre-round shares). Post-money shares = pre-round shares + new shares. Your new ownership = your shares ÷ post-money shares.