How to use the equity dilution calculator
When a company raises money it issues new shares, and every existing shareholder ends up with a smaller percentage. Enter your ownership before the round, the pre-money valuation, the new investment and any option pool you are creating to see where your stake lands once the round closes.
Post-money valuation is the pre-money valuation plus the new investment, and the investor's percentage is the investment divided by that post-money number. The option pool changes the picture: a pre-money pool comes out of the existing holders alone, while a post-money pool dilutes every shareholder equally, including the new investor. Pick the option that matches your term sheet, because the two produce very different outcomes for founders.
The change-in-value line subtracts the value of your stake before the round from the value after. With no new pool, your percentage drops but the value stays flat. This tool models common-stock dilution only and does not convert SAFEs or notes.
Frequently asked questions
A pre-money pool is carved out of the existing shareholders only, so founders and early holders absorb all of that extra dilution. A pool created after the round dilutes everyone, including the new investor, by the same percentage. Investors often ask for a pre-money pool, so check the term sheet for which one applies.
Not necessarily. With a straight share issuance and no new pool, your percentage falls but the value of your stake stays the same, because the company is worth more by exactly the amount invested. Raising at a higher valuation can leave you with a smaller slice of a bigger pie.
No. This tool models straight common-stock dilution only. Converting SAFEs or notes, liquidation preferences and anti-dilution provisions are not calculated here, and any of them can make your real dilution larger.