Worked Example: Modeling Dilution from Seed to Series B
This post is a numerical companion to Modeling Dilution Across Multiple Rounds.
Its purpose is not theory or judgment, but demonstration.
The example below walks through a realistic US / Canadian venture-backed path from founder ownership through Seed and Series B, showing how dilution compounds even when terms are market-standard.
No aggressive structure. No bad behavior. Just math.
How does founder ownership dilute from Seed to Series B?
Founder ownership typically declines through option pool creation, pre-money pool refreshes, and successive equity rounds, often falling to 35–40% by Series A and lower by Series B—even with standard terms.
Starting Point: Pre-Seed / Founders Only
Assumptions (typical Delaware or CBCA startup):
- Authorized shares: 10,000,000 common
- Issued to founders: 8,000,000
- Unissued: 2,000,000
- Option pool: none
Fully diluted (FD): 8,000,000
Founder ownership: 100% FD
At this stage, ownership looks clean because future dilution has not yet been allocated.
Step 1: Pre-Seed Option Pool Creation
Before raising capital, the company creates an employee option pool.
- Target pool: 10% post-pool
- Pool shares issued: 1,111,111
- Total FD after pool: 11,111,111
- Options granted early: 500,000 (from pool)
Post-pool FD ownership:
- Founders: ~72%
- Pool (granted + unallocated): ~28%
Dilution before any investor enters: ~28%
This dilution is often overlooked because no money changed hands.
Step 2: Seed Round (Priced Equity)
Raise $2M at an $8M pre-money valuation
Post-money: $10M
Term sheet requires:
- 15% post-money option pool
Actions:
- Pool refresh issued pre-money
- New investor buys 20% of the company
After issuing pool top-up and Seed shares:
Fully diluted shares: ~12,500,000
FD ownership post-Seed:
- Founders: ~64%
- Seed investors: ~16%
- Option pool (total): ~20%
Cumulative founder dilution: 100% → ~64%
No unusual terms. Entirely standard.
Step 3: Series A
Raise $8M at $32M pre-money
Post-money: $40M
Terms:
- Pool refreshed to 15% post-money
- Investors purchase 20%
Pre-money dilution occurs again via pool refresh.
Post-Series A FD ownership:
- Founders: ~40%
- Seed investors: ~10%
- Series A investors: ~25%
- Option pool: ~25%
Cumulative founder dilution: 100% → ~40%
This is where many founders first feel surprised—even though nothing unusual happened.
Step 4: Bridge or Inside Round (Optional but Common)
Assume:
- $5M bridge converts at a discount
- 1,000,000 options exercised
After conversion:
- Founders fall to ~35–37% FD
- Exact number depends on anti-dilution mechanics
Still no failure. No misconduct. Just compounding.
What This Example Demonstrates
- Option pools are first-order dilution, not footnotes.
- Each round compounds prior dilution, even at “only” 20%.
- Founder outcomes are determined early, before leverage is strongest.
- Fully diluted ownership is the only meaningful metric.
- Downside scenarios accelerate dilution, but are not required for it.
A founder at ~35–40% after Series A is normal.
A founder below ~20% by Series B is a warning signal—to both sides.
How Investors Use This Model
Investors run this path backward from exit expectations.
They ask:
- Will founders still be motivated at exit?
- Will refresh grants be required?
- Who absorbs dilution if growth slows?
This is why investors focus less on today’s percentages and more on structural survivability.
Founder Takeaway
Dilution is inevitable.
The variables are how much, how early, and who bears it.
A single 10% pool concession today can translate into 5–8% less ownership at exit—even without a down round.
Model the full path before signing any term sheet.
Note
This worked example is illustrative only. Actual outcomes depend on structure, timing, and negotiated terms. Founders should review dilution scenarios with qualified legal and financial advisors.
Cap tables do not drift randomly.
They follow the path you set early—one round at a time.