The math behind the YC deal
- 7%
- YC's fixed stake for $125K
- $500K
- The YC standard deal since 2022
- 12
- Languages supported
- Free
- No credit card required
Free founder calculator
See what your SAFE really costs before you sign it
Drop in the SAFE amount, the post-money cap and, if you have one, the discount. Add your next round to see how the SAFE converts and what is left for founders.
SAFE amount
Post-money valuation cap
Discount (optional)
Next round pre-money (optional)
Next round raise (optional)
Your live result
Enter the SAFE amount and the post-money cap to see the stake you are selling.
Stack every SAFE on one cap table, free
Sign up to model several SAFEs at once (including YC's $125K plus $375K MFN pair), an option pool top-up and your Series A on one table, then find the investors who fund your stage.
- Ownership sold at signing, the YC post-money rule: amount divided by cap
- Cap versus discount at your priced round, and the stake left after new money
- Free. No card. Localized in 12 languages.
Used by founders raising at YC, Techstars, 500, Antler, and Google for Startups.
Created by founders from top global accelerators
How it works
Two numbers give you the stake. Three more give you the round.
- 01
Enter the SAFE amount and the post-money cap
Ownership under a post-money SAFE is the amount divided by the cap. $500K on a $10M cap is 5 percent, fixed at signing.
- 02
Add a discount if the SAFE has one
At conversion the investor gets the lowest price available: the cap price, the discounted round price or the round price. The calculator shows which one applies to your numbers.
- 03
Model the priced round
Enter the next round's pre-money and raise. New money dilutes everyone who was there before, the SAFE holder included, and you see the stake that is left.
What the YC post-money SAFE actually does
Four things founders learn the expensive way.
01
Every SAFE you sign after YC dilutes only you
A post-money SAFE fixes the investor's percentage at signing. Later SAFEs do not dilute earlier ones; they come out of the founders' share. Stack three of them and the founders absorb all three.
02
YC's 7 percent is a $1.79M post-money cap in disguise
$125,000 for 7 percent is the same as a post-money SAFE with a cap of about $1.79M. The $375,000 MFN SAFE has no cap: it takes the best terms of any SAFE you sign before the priced round.
03
The cap only matters if it is below your next round
Raise at a pre-money above the cap and the investor converts at the cap, keeping the stake they had at signing. Raise below it and they convert at the round price (or the discounted price) instead, so the cap was never the binding term.
04
The option pool top-up at the round dilutes the SAFE too
The post-money cap counts every SAFE, note and option already in the pool before the priced round. A pool increase done as part of the round sits outside that count, so it dilutes the SAFE holder along with the founders and every other pre-round holder.
Frequently asked questions
How is ownership calculated on a YC post-money SAFE?
Amount divided by the post-money valuation cap. $500K on a $10M cap is 5 percent, fixed at signing and unchanged by any SAFE signed afterwards. The priced round then dilutes it like every other pre-round stake.
What is the difference between a pre-money and a post-money SAFE?
A pre-money SAFE's cap excludes the SAFE money itself, so the investor's percentage shrinks as more SAFEs are signed. YC's post-money SAFE, its standard since 2018, fixes the percentage at signing; later SAFEs dilute the founders, not earlier investors.
Does the cap or the discount apply at conversion?
Whichever gives the investor the lower price per share. If your next round's pre-money is above the cap, the cap applies. If it is below, the discounted round price applies. The calculator shows which one wins for your inputs.
What does YC's $125K for 7 percent equal as a cap?
About $1.79M post-money ($125,000 divided by 7 percent). The second YC SAFE, $375K with an MFN clause, has no cap and takes the best terms of any SAFE you sign before the priced round.
How much does a SAFE dilute founders?
By the stake sold: amount divided by cap. A $1M SAFE on a $10M post-money cap sells 10 percent, and three such SAFEs sell 30 percent, all of it out of the founders' share. Model the stack before signing the third one.
Is this calculator legal or financial advice?
No. It is the arithmetic of YC's published post-money SAFE, run on hypothetical inputs. Share counts in a real conversion also depend on the option pool top-up and other converting securities, so have counsel check the final cap table.
Keep going
The SAFE is one line on the cap table. Here is the rest.
Round Funded
Know your dilution. Raise the round.
Round Funded gives you the numbers, the investors and the outreach so you raise on real terms, not guesses. Track every send and reply in one pipeline.