Dilution Calculator

How to use it

1. Add each funding round in sequence with a name, the investment amount, and the pre-money valuation. The order matters because dilution compounds: each round's new investors take their slice of what is left after every prior round, not of the original cap table. Use real or quoted terms rather than round numbers, because a $2M pre-money on a $500K raise dilutes very differently from a $4M pre-money on the same cheque.
2. Set your ownership before the first round (100% solo, 50% for one of two equal co-founders) and any new option pool a round requires, then read the per-round list: each round's terms, your remaining ownership and the paper value of your stake. The new investor's percent is the investment divided by post-money valuation, and your stake is multiplied down by (1 minus that fraction minus the new pool) every time. Watch the founder ownership column fall across rounds, because that compounding is the number most founders underestimate when they model only the round in front of them.
3. Treat the final founder ownership figure as the real cost of the capital, not the headline valuation. A higher pre-money on each round protects ownership, so this is where you see whether a generous-looking valuation actually preserves your stake or whether stacking several rounds quietly leaves you with a minority position before you reach an exit.
4. Model the bootstrapped alternative by comparing what 100% of a smaller, self-funded outcome is worth against your diluted percentage of a larger, venture-backed one. If raising three rounds leaves you with 45% of the company, the venture path only wins if the funding more than doubles the eventual exit value. Test a tighter raise (less capital, same valuation) to see how much ownership a leaner round preserves.
5. Re-run before signing any term sheet and again whenever option pools, bridge rounds, or down-rounds enter the picture, since those dilute founders the hardest. Save the scenario so you can compare a two-round plan against a single larger raise, and use it alongside the business valuation tool to translate ownership percentages into actual dollar outcomes.

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Use it from code

The same calculation as a JavaScript module you can import. It runs where you import it, with no request, key or rate limit.

import { compute } from "https://aibizhub.io/engines/dilution-calculator.js";

Input and output contract, TypeScript types and the guide for agents.