Free tool
Startup Equity & Dilution Calculator
See exactly what your stake becomes after a priced round, and what the investors take.
What you still own once a priced round closes, what the investors take, and what the option pool quietly costs you.
- Your ownership now
- Pre-money valuation
- Amount raising
Calculate dilution
Example
Your ownership now 60% · Pre-money valuation $8,000,000
48.00%
Your ownership after the round
How it works
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1
Enter your numbers
Fill in your ownership now, pre-money valuation and amount raising. Change a number and the answer updates.
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2
Press calculate dilution
One button. Change any input afterwards and the answer updates as you type.
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3
Read the result
You get your ownership after the round, plus post-money valuation, investors take, your stake is worth.
How dilution works
Post-money valuation is pre-money plus the amount raised. The investors own the money they put in as a share of that post-money figure. Raise $2m on an $8m pre-money and post-money is $10m, so investors take 20%.
Everyone already on the cap table is diluted by that same 20%, proportionally. If you owned 60%, you now own 60% x 0.8 = 48%. Your percentage falls, but it falls against a company that just became more valuable — 48% of $10m is more than 60% of $8m.
The option pool shuffle
This calculator excludes the option pool, and that omission is deliberate — the pool is usually where the real negotiation happens.
Investors typically require an employee option pool of 10-15%, created or topped up before the round closes. Because it comes out of the pre-money valuation, existing shareholders absorb all of it. An $8m pre-money with a 10% pool top-up is effectively a $7.2m pre-money for you, and your post-round stake is meaningfully smaller than the headline numbers suggest. Always ask whether a quoted pre-money is before or after the pool.
Dilution across multiple rounds
Dilution compounds. Founders commonly hold 50-60% after seed, 30-40% after Series A, and 15-25% after Series B. Arriving at an exit with 10-20% as a founding team is a normal outcome, not a failure.
The question is never how to avoid dilution — it is whether each round buys enough growth to make the smaller slice worth more. Raising less at a lower valuation is not automatically better if it means you cannot reach the milestones the next round requires.
What this does not model
Convertible notes and SAFEs from earlier rounds convert at this priced round, often at a discount or valuation cap, and they can take a considerably larger share than their face value implies. Liquidation preferences, participation rights and anti-dilution provisions all change what you actually receive at exit regardless of percentages.
For a real round, model the full cap table including converting instruments, and have a lawyer check the terms. Percentages are only part of the picture.
What this does not do
- Excludes the option pool. Investors usually require one created pre-money, which dilutes you further than the headline numbers suggest.
- Does not model SAFEs or convertible notes. Those convert at a priced round, often at a discount or cap, and can take more than their face value implies.
- Percentages are only part of the outcome. Liquidation preferences and participation rights change what you actually receive at exit.