Startup Valuation & Dilution Calculator: Pre-Money, Post-Money, Ownership
Raising money? See exactly how much of your company an investment buys, how much the founders keep and what each share is priced at.
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Pre-Money, Post-Money and Ownership
Investor ownership = Investment ÷ Post-money valuation
Price per share = Post-money valuation ÷ Shares after the round
Example: An investor puts in 1 million at a 4 million pre-money valuation. Post-money is 5 million and the investor owns 20%. With a new 10% option pool, founders who owned 100% keep 70%.
Works in any currency — enter all amounts in the same one.
Founder Ownership Through Typical Rounds
Illustrative dilution if each round sells 20% and adds a 10% option pool (pool created before the investment):
| After | Founders keep |
|---|---|
| Seed round | 70% |
| Series A | 49.00% |
| Series B | 34.30% |
Real rounds vary — later rounds often sell a smaller share, and pool top-ups may be smaller.
The Option Pool Shuffle
Investors usually ask for the employee option pool to be created before their money comes in, so it dilutes the existing shareholders rather than the investor. A larger pool lowers the founders’ stake and the effective pre-money valuation — negotiate its size based on a real hiring plan.
Not Included
- SAFEs and convertible notes, which convert at a discount or valuation cap.
- Liquidation preferences, which decide who is paid first in a sale.
- Anti-dilution protection in later down rounds.
Frequently Asked Questions
What is pre-money valuation?
The value agreed for the company just before the new investment. Adding the investment gives the post-money valuation.
How much equity should I give up in a seed round?
Seed rounds commonly sell 10%–25% of the company. Selling more early leaves less room for later rounds.
Why does the option pool reduce founder ownership?
When the pool is created before the investment, its new shares come out of the existing owners’ stake, not the investor’s.
What is fully diluted ownership?
Ownership counting all shares that could exist — issued shares plus the option pool and any convertible securities.