One SAFE, then a seed round
$500k on an $8M cap, then a $3M seed at a $12M pre-money valuation with a 10% option pool.
Result: Founders keep 65.0% after the round
Free tool
SAFE dilution calculator
Add your SAFEs, then the priced round they convert into, to see who owns what afterwards — founders, SAFE holders, the option pool and the new investors.
SAFEs
Next priced round
Founders keep 62.9% after the round
Post-money valuation $15M · new investors buy 20.0%
- Founders62.9%
- SAFE 1 ($500k)5.0%
- SAFE 2 ($250k)2.1%
- Option pool10.0%
- New investors20.0%
Simplified model: each SAFE converts at the better of its cap or the discounted round valuation, and the pool is created before the new money. Real conversion depends on your SAFE wording — check with your lawyer.
Updated Oct 1, 2026
Worked examples
Stacked SAFEs into a Series A
$250k at a $5M cap and $750k at a $10M cap convert into a $4M round at $16M pre, with a 12% pool.
Result: Founders keep 58.0% after the round
Discount only, no cap
$500k with a 20% discount and no cap, converting into a $2.5M round at $10M pre.
Result: Founders keep 65.0% after the round
How it works
Each SAFE converts at whichever is better for the investor: its valuation cap, or the round's pre-money valuation less its discount. That gives each SAFE holder a stake before the new money comes in. The option pool is sized so it hits your target after the round but is created beforehand (the usual "pool shuffle"). Finally the new investors buy their stake, diluting everyone who was there before.
It's a simplified model of the YC post-money SAFE. Real conversion depends on your exact SAFE wording, so check the numbers with your lawyer.
Outside the US
SAFEs are a US instrument. In the UK, founders more often use advance subscription agreements (ASAs), which can be structured to fit SEIS/EIS. Indian startups often use instruments such as iSAFE notes or compulsorily convertible preference shares (CCPS); other markets have local SAFE-style or convertible-note templates.
The ownership maths here — cap or discount, then dilution in the priced round — carries over; the legal terms don't, so check yours with a local lawyer.
Common questions
How much dilution does a SAFE cause?
Roughly the amount invested divided by the valuation it converts at — the cap, or the discounted round price if that's lower — and then that stake is diluted again by the priced round itself.
Is a lower valuation cap worse for founders?
Yes. A lower cap means the SAFE converts into more shares, so investors own more and founders less. Discounts work the same way when the round is priced below the cap.
What is the option pool shuffle?
Investors usually ask for the option pool to be created or topped up before their money comes in, so the new pool dilutes existing holders — founders and SAFE holders — rather than the new investors.
Read more: SAFE vs convertible note · Valuation cap · Dilution · Cap table calculator
General information, not legal, tax or investment advice.