This calculator estimates the percentage of a company sold in a pre-seed financing round and the founders’ remaining ownership immediately after the investment. It uses the pre-money valuation and new cash invested to calculate the post-money valuation and investor ownership.
The output is useful for negotiating round size, comparing term-sheet scenarios, and understanding the ownership tradeoff of raising more capital. It does not model option-pool changes, multiple security classes, SAFEs, notes, or later dilution unless those effects are already reflected in the valuation inputs.
1. Set the pre-money valuation
Enter the negotiated company value immediately before the new investment.
2. Enter the round amount
Use only the new money included in this financing scenario.
3. Add current founder ownership
Enter the founders’ combined ownership before the round.
4. Compare ownership outcomes
Review investor equity, post-money valuation, and founder ownership after closing.
Post-money valuation = Pre-money valuation + Investment Investor equity % = Investment ÷ Post-money valuation × 100 Founder ownership after = Founder ownership before × (1 − Investor equity %)
The model assumes a straightforward priced equity round with no simultaneous option-pool increase or convertible conversion.
The main result is the percentage of post-money equity attributable to the new investment.
Legal documents and capitalization-table mechanics can produce different results.
Given: $4,000,000 pre-money valuation, $800,000 investment, and founders owning 100% before the round.
Calculation: Post-money value = $4,800,000. Investor equity = $800,000 ÷ $4,800,000 = 16.67%. Founder ownership after = 100% × 83.33% = 83.33%.
Result: The investor receives 16.67% and the founders retain 83.33%.
No. It calculates ownership percentages from valuation and investment amounts, not the number or price of shares.
Enter the pre-money valuation. The calculator derives post-money valuation by adding the investment.
A pre-money option-pool increase can dilute existing holders more than this simplified model shows.
Only as a rough economic illustration. SAFE conversion depends on its valuation cap, discount, and financing terms.
If founders own less than 100% before the round, their percentage-point reduction is smaller than the investor’s total stake.