Multi-round dilution
Dilution calculator: founder ownership across every round
Build your founders, pool, SAFEs and priced rounds in order — Foundily runs the full scenario and charts how founder ownership erodes at each stage, so you can see the real cost of a round before you sign it.
Founders
Financing events, in order
Founder ownership by round
| Stakeholder | Type | Invested | Shares | Ownership |
|---|---|---|---|---|
| Founder A | Common | — | 6,000,000 | 39.13% |
| Founder B | Common | — | 4,000,000 | 26.09% |
| Option Pool | Options | — | 1,533,333 | 10.00% |
| Seed SAFE | SAFE | $500K | 733,333 | 4.78% |
| Series A | Preferred | $4M | 3,066,667 | 20.00% |
| Total (fully diluted) | 15,333,333 | 100% | ||
Show cap table at each stage
Series A
| Stakeholder | Type | Shares | Ownership |
|---|---|---|---|
| Founder A | Common | 6,000,000 | 39.13% |
| Founder B | Common | 4,000,000 | 26.09% |
| Option Pool | Options | 1,533,333 | 10.00% |
| Seed SAFE | SAFE | 733,333 | 4.78% |
| Series A | Preferred | 3,066,667 | 20.00% |
| Total (fully diluted) | 15,333,333 | 100% | |
How it works
1. Set your starting cap table
2. Add events in the order they happen
3. Read the founder trail
4. Expand any stage
Frequently asked
Why does founder ownership drop even between two rounds with no new round in between?+
It doesn't in this model — ownership only moves at a priced round, where pending SAFEs convert and any new option pool is created. Adding a SAFE by itself just queues it; the dilution shows up at the next priced round.
Does the option-pool top-up dilute the new investor?+
No. A round's pool top-up is created pre-money, so it dilutes existing holders (founders and converting SAFEs) — the new investor's target ownership is unaffected by how big the pool refresh is.
Can I model a scenario with no priced rounds yet, only SAFEs?+
Yes — add SAFEs without a following round and the final cap table will show them as outstanding, unconverted securities alongside your founders and pool.
How is this different from the cap table calculator?+
The cap table calculator models a single point in time (one round). This dilution calculator threads an ordered sequence of rounds and SAFEs so you can see the trend across your company's whole financing history.
Need this in your own tool or agent?
The exact same engine is available as a JSON API — one key, deterministic results, an OpenAPI spec and an MCP server.