Startup Equity Dilution Calculator
See how much of your company you actually keep after a sequence of funding rounds. Set your starting stake, then add each round's raise, pre-money valuation and option pool to watch your ownership dilute over time.
Your stake
Funding rounds
Each round issues new shares, so your percentage shrinks. Add the raise, the pre-money valuation and any new option pool (carved pre-money).
Round-by-round dilution
| Round | Raise | Post-money | Round dilution | Your % after | Your value |
|---|
How equity dilution works across rounds
Every priced round issues new shares. Your share count doesn't change, but the total grows, so your percentage falls. For a single round the new investor takes raise ÷ post-money (post-money = pre-money + raise). A new option pool is usually carved pre-money, which dilutes existing shareholders, including you, on top of the investor's stake.
Across several rounds, dilution compounds. If you keep 80% through a round and 85% through the next, you're left with 0.80 × 0.85 = 68% of what you started with. This calculator applies each round in order and multiplies the effect, so the final number reflects the full Seed → Series A → B → … path, not just one round.
Founders commonly end up with a 10–20% stake by the time a company is several rounds in. To protect ownership, focus on round size, valuation and how large a pool each investor asks you to create. For the full per-shareholder breakdown of a single round, use the cap table calculator; to plan the raises themselves, see the SaaS fundraising guide. This tool is a fast estimate, not legal or investment advice.
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Model dilution against runway and hiring
Adlega ties your ownership to the actual financial plan, so you can see how each raise affects dilution, runway and the milestones it has to buy.