SAFE Note Stacking: How Multiple SAFEs Convert at a Priced Round
In this guide
You raised $250K on a $5M cap SAFE in January. Then another $500K on an $8M cap in March. Then a $1M MFN SAFE in May. Now your Series A is priced at $20M pre-money. What happens to your cap table?
This is SAFE stacking — and it's one of the most confusing things founders face during fundraising. Let's break it down step by step.
What is SAFE stacking?
SAFE stacking happens when a startup raises money through multiple SAFE notes at different terms before a priced round. Each SAFE has its own valuation cap, discount, and investment amount. When a priced round finally happens, all SAFEs convert at once, but each at its own conversion price.
This is extremely common. Most pre-seed startups raise from 3-5 angels using SAFEs, often with different terms negotiated by each investor.
How multiple SAFEs convert
Each SAFE converts independently based on its own terms. Here's the key insight: a lower valuation cap or higher discount means more shares for that investor, which means more dilution for you.
For each SAFE, the conversion price is calculated as:
Conversion Price Rules
Discount Only: Conversion Price = Price Per Share × (1 - Discount%)
Cap + Discount: Conversion Price = min(Cap Price, Discounted Price)
MFN: Gets the best price of any other SAFE in the round
Once you have the conversion price for each SAFE:
Ownership % = Shares Issued / (Pre-Money Shares + All SAFE Shares) × 100
Example: 3 SAFEs at different caps
Let's work through a real scenario with actual numbers.
Setup
Pre-money valuation: $20M | Price per share: $10.00
Pre-money shares outstanding: 2,000,000
| SAFE | Investment | Cap | Discount | Type |
|---|---|---|---|---|
| Angel SAFE 1 | $250,000 | $5M | 20% | Cap + Discount |
| Angel SAFE 2 | $500,000 | $8M | — | Cap Only |
| Angel SAFE 3 | $1,000,000 | — | — | MFN |
Step 1: Calculate conversion price for each SAFE
Angel SAFE 1 ($250K, $5M cap, 20% discount)
Discount Price = $10 × (1 - 0.20) = $8.00
Conversion Price = min($2.50, $8.00) = $2.50
Angel SAFE 2 ($500K, $8M cap, no discount)
Conversion Price = $4.00
Angel SAFE 3 ($1M, MFN)
Conversion Price = $2.50 (matches the best deal)
Step 2: Calculate shares and ownership
Share Calculation
Angel SAFE 2: $500,000 / $4.00 = 125,000 shares (5.68%)
Angel SAFE 3: $1,000,000 / $2.50 = 400,000 shares (18.18%)
Total SAFE Shares: 625,000
Total Fully Diluted: 2,000,000 + 625,000 = 2,625,000
The SAFE Waterfall: Founder Dilution Step by Step
Here's where the stacking effect becomes clear. Watch the founder ownership drop with each SAFE:
| Step | Event | Founder Ownership | Change |
|---|---|---|---|
| 1 | Before SAFEs | 100.00% | — |
| 2 | After Angel SAFE 1 converts | 95.24% | -4.76% |
| 3 | After Angel SAFE 2 converts | 89.52% | -5.72% |
| 4 | After Angel SAFE 3 (MFN) converts | 71.43% | -18.09% |
| Final Founder Ownership | 71.43% | -28.57% |
Key insight: Angel SAFE 3 (the MFN SAFE) caused the most dilution because it matched the lowest cap price ($2.50) while investing the most money ($1M). MFN SAFEs can be very expensive for founders when they match a low cap and invest a large amount.
5 Common Mistakes with Stacking SAFEs
1. Not tracking cumulative dilution
Each SAFE seems small on its own, but they add up. Three SAFEs that each dilute you 5-8% can leave you with 70% ownership before the Series A even starts.
2. Underestimating MFN SAFEs
MFN (Most Favored Nation) SAFEs inherit the best terms of any other SAFE. If you gave one angel a $5M cap, every MFN investor also gets that $5M cap — no matter how much they invested.
3. Ignoring the "stacking effect" on future rounds
If SAFEs take 28% of your company, and then your Series A takes 20%, you're left with: 71.43% × 80% = 57.1%. After option pool creation (typically 10%), you're at 51.4%. That's before Series B.
4. Not modeling before signing
Always model the full SAFE conversion before accepting a new SAFE. Use the SAFE Note Calculator to see exactly what each new SAFE does to your cap table.
5. Forgetting SAFE dilution affects employees too
Your option pool gets diluted by SAFEs too. A 10% option pool pre-SAFE becomes 7.1% after the SAFEs in our example. You may need to increase the pool — which dilutes founders further.
Model your own SAFE stacking scenario
Our SAFE Note Calculator handles multiple SAFEs with different caps, discounts, and MFN provisions. It shows you the full waterfall — exactly how your ownership changes as each SAFE converts.
Try the SAFE Stacking Calculator
Add up to 6 SAFEs with different terms and see exactly what happens to your cap table.
Open SAFE Calculator →