Equity dilution calculator
Useful for founders before signing a round: see how much your stake shrinks in return for the money coming in.
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How to use it
- Enter pre-money valuation, investment amount and your stake before the round.
- The result appears straight away and updates as you edit.
- Copy the result, or copy a link that keeps the same values to share it.
How it is calculated
Post-money = pre-money + investment. Investor stake = investment ÷ post-money. Your stake after = your stake before × (pre-money ÷ post-money).
Example
Inputs: Pre-money valuation = 4,000,000, Investment amount = 1,000,000, Your stake before the round = 60 %. Result: Your stake after the round: 48%; Post-money valuation: 5,000,000.00; New investor stake: 20%.
Limits and caveats
- Does not model an option pool top-up or conversion of SAFEs and convertible notes, which all dilute further.
- Assumes a single priced round of shares.
Questions about this tool
Does dilution mean I lost money?
Not necessarily. Your percentage falls, but your stake at the new valuation is worth what it was at the old one, and the company now has more cash.
What is the difference between points and dilution percent?
Going from 60% to 48% is a 12 point drop, while dilution is 20% because you gave up one fifth of what you owned.
Why is dilution the same for every shareholder?
In a single priced round every existing holder is diluted by the same factor, equal to the new investor stake.