Business
Startup Equity Dilution Calculator
Enter your current ownership stake, the company's pre-money valuation, how much new capital is being raised, and any new option pool, to see your post-round ownership and how many percentage points you're diluted.
See how a new funding round (and option pool top-up) affects your ownership stake.
Post-round ownership
Post-money = Pre-money + Raise; New ownership = Current % × (1 − New investor % − Option pool %)
New investors' ownership comes from the raise divided by the post-money valuation. Everyone else's stake — including any new option pool carved out for hiring — is diluted proportionally by what's left over.
How to use
- Enter your current ownership percentage before the round.
- Enter the round's pre-money valuation and how much capital is being raised.
- Add any new option pool percentage being created as part of the round — pools are usually carved out of existing shareholders, not just new investors.
Example
Input: 10% ownership, $8M pre-money, $2M raise, 0% new pool
Output: New ownership ≈ 8%, diluted by 2 points
Student-friendly breakdown
This walkthrough emphasizes the most searched ideas for Startup Equity Dilution Calculator: equity dilution calculator, startup dilution calculator, cap table dilution calculator, how much will i be diluted funding round. Start with the formula above, then follow the guided steps to double-check your work. For quick revision, highlight the givens, plug into the equation, and finish by verifying your units.
Need more support? Use the links below to open the long-form guide, browse additional examples, or hop into adjacent calculators within the same topic — each one is a quick way to double-check your work or handle a related question without starting from scratch.
Deep dive & study plan
Startup Equity Dilution Calculator: Shows how a new funding round and option pool affect your ownership percentage. It's built around equity dilution calculator, startup dilution, cap table, so you can go from a raw question to a checked answer without switching tools.
The math behind it: New investors' ownership comes from the raise divided by the post-money valuation. Everyone else's stake — including any new option pool carved out for hiring — is diluted proportionally by what's left over. The core relationship is Post-money = Pre-money + Raise; New ownership = Current % × (1 − New investor % − Option pool %), shown above the calculator so you can see exactly how your inputs turn into the result.
To use it well: (1) Enter your current ownership percentage before the round. (2) Enter the round's pre-money valuation and how much capital is being raised. (3) Add any new option pool percentage being created as part of the round — pools are usually carved out of existing shareholders, not just new investors. Keep your units consistent as you go, and re-run a case you already know the answer to — it's the fastest way to catch a typo before it throws off a result you're relying on.
Worked example: entering 10% ownership, $8M pre-money, $2M raise, 0% new pool returns New ownership ≈ 8%, diluted by 2 points. Try swapping in your own numbers next, especially a case you're unsure about, before you use this for something that matters.
Quick retention checklist
- Speak the formula aloud (or annotate it) so the relationships stick.
- Write each step in your own words and compare with the numbered list above.
- Swap in new numbers for the Example to make sure the calculator (and your logic) handles edge cases.
- Check at least one related calculator below — it's the fastest way to confirm your numbers still line up from a different angle.
FAQ & notes
Why does adding an option pool dilute me more than the investor's cash alone?
Investors typically require the option pool to be created before their money comes in, which means existing shareholders — not the new investor — absorb most of the pool's dilution. This is a common negotiating point in term sheets.
Is dilution always bad?
Not necessarily — a smaller percentage of a much larger company can be worth more than a larger percentage of a small one, provided the new capital is used to genuinely grow the company's value.
What formula does the Startup Equity Dilution Calculator use?
New investors' ownership comes from the raise divided by the post-money valuation. Everyone else's stake — including any new option pool carved out for hiring — is diluted proportionally by what's left over.
How do I use the Startup Equity Dilution Calculator?
Enter your current ownership percentage before the round. Enter the round's pre-money valuation and how much capital is being raised. Add any new option pool percentage being created as part of the round — pools are usually carved out of existing shareholders, not just new investors.