Valuation Cap Calculator
A valuation cap calculator shows what a SAFE (Simple Agreement for Future Equity) actually turns into when your priced round closes. The cap is the maximum valuation your SAFE converts at; the discount is a percentage off the round price; the investor gets whichever is better for them. This tool computes the conversion price per share, the shares the SAFE holder receives, the ownership percentage, and which term binds, so founders can see the dilution before they sign.
The model follows the post-money SAFE mechanics Y Combinator standardized: ownership equals investment divided by the post-money cap, locked in at signing. If you are dividing founder equity before the raise, start with the commission-to-equity ratio logic for splits; if you are reserving an option pool alongside the SAFEs, check how pool sizing hits the table through an equity compensation plan; and the margin those future shares need to protect is your equity margin on every decision.
SAFE conversion price, shares, ownership, and which term binds
A planning model of post-money SAFE mechanics, not legal advice. Confirm terms with your startup attorney before signing.
Quick Answer
Key takeaways
- Conversion price = the lower of (cap / shares) and (round price x (1 – discount)). The investor always gets the better deal.
- On a YC post-money SAFE, ownership = investment / cap, locked at signing. A $250K check on an $8M cap is 3.125%, period.
- Set the cap at roughly 30–50% of your realistic Series A valuation 18–24 months out, and never below your total dilution ceiling.
- Pre-money and post-money SAFEs convert differently. Know which form you signed before you model anything.
How a valuation cap actually works
A SAFE is not a loan: no interest, no maturity date, no shares today. It is a promise of future equity, and the valuation cap is the ceiling on the price of that equity. If your Series A prices at $20M and your SAFE cap is $8M, the SAFE investor converts as if the company were worth $8M, which buys them two and a half times the shares a Series A investor gets for the same dollars. The cap is the investor’s reward for betting earliest, when the risk was highest.
Cap vs discount: which one binds
Most SAFEs carry both a cap and a discount, and they protect the investor in opposite scenarios. The cap matters when you outperform: a hot Series A at a high valuation would otherwise dilute the early check, so the cap locks in the cheap conversion. The discount matters when you price modestly: if the Series A lands at or below the cap, the cap is worthless and the discount is the only benefit the SAFE holder gets. The tool compares both prices and tells you which one binds for your numbers.
Valuation cap binds
- Series A prices above the cap
- Conversion price = cap / shares
- Investor’s reward for early risk
- A low cap means heavy founder dilution
Discount binds
- Series A prices at or below the cap
- Conversion price = round price x (1 – discount)
- Guaranteed cheaper entry than the round
- A cap set too high becomes decoration
Worked example: $250K on an $8M cap into a $20M Series A
With 8 million fully diluted shares outstanding, the Series A share price is $20M / 8M = $2.50. The cap price is $8M / 8M = $1.00. The discount price is $2.50 x 0.80 = $2.00. The lower price wins, so the SAFE converts at $1.00 per share: $250,000 / $1.00 = 250,000 shares, or 3.125% of the company. Had the discount applied instead, the same check would have bought only 125,000 shares. That 125,000-share gap is the dollar value of negotiating the cap correctly.
| Scenario | Series A valuation | Binding term | Conversion price | Shares for $250K |
|---|---|---|---|---|
| Hot round | $20M | Cap | $1.00 | 250,000 |
| At the cap | $8M | Discount | $0.80 | 312,500 |
| Down round | $6M | Discount | $0.60 | 416,667 |
The middle row deserves a note: at an $8M Series A with 8M shares, the round price is $1.00, the cap price is $1.00, and the 20% discount price is $0.80, so the discount wins outright. Whenever the round prices at or below the cap, the discount is the binding term. Those are the tool’s exact outputs when you change the pre-money valuation field.
Post-money vs pre-money SAFEs
Y Combinator’s current standard is the post-money SAFE: the cap includes all SAFE money, so ownership equals investment divided by cap, and founders know the dilution the day they sign. Older pre-money SAFEs exclude the SAFE money from the cap math, which makes the same headline cap more dilutive than it looks. If you are modeling with this tool, confirm which form your note uses; the ownership math here follows the post-money standard.
What competing SAFE calculators miss
Most free SAFE calculators model pre-money notes even though the market moved to post-money SAFEs years ago, which quietly understates founder dilution. Many show a conversion price but never name which term binds, so founders cannot see whether their cap is doing any work at all. And almost none of them show the discount-only comparison: without it, you cannot tell whether the cap you negotiated was worth the dilution it cost.
This tool models the post-money standard, states the binding term explicitly with a verdict badge, and shows the discount-only share count side by side so the value of your cap is visible in shares, not just theory.
Frequently Asked Questions
The maximum valuation at which a SAFE converts into equity. If the priced round values the company above the cap, the SAFE holder converts as if the valuation were the cap, which buys them more shares. It protects early investors against the company getting much more valuable before the priced round.
At conversion the investor gets the better of the two: the lower of (cap / fully diluted shares) and (round share price x (1 – discount)). If the round prices high, the cap binds; if it prices at or below the cap, the discount binds. Most SAFEs include both.
PitchBook-NVCA data puts the median pre-seed cap around $7.7M and the median seed cap around $15.8M, with AI companies commanding more. A defensible cap sits at roughly 30 to 50 percent of your realistic Series A valuation 18 to 24 months out.
On a post-money SAFE (the YC standard), the cap includes all SAFE money, so ownership equals investment divided by cap and founders know the dilution at signing. On a pre-money SAFE, the cap excludes the SAFE money, making the same headline number more dilutive. This calculator models post-money mechanics.
On a post-money SAFE, divide the investment by the cap: $250K on an $8M cap is 3.125% dilution. Add up every SAFE on the same terms to get total pre-round dilution, and keep it under your ceiling (many founders target under 20% across all SAFEs before a priced round).
Yes. The cap simply does not bind in that case; the discount does. The SAFE holder converts at the discounted round price, which can mean more shares (and more dilution) than the headline ownership percentage implied.
Yes. SAFEs are securities with real legal consequences (MFN clauses, pro-rata rights, conversion triggers). A calculator models the math; a startup attorney makes sure the documents say what you think they say. Budget for counsel before you take money.
References
- Eqvista. How Founders Set the Valuation Cap on a SAFE Note. Accessed October 19, 2026.
- Raziel. SAFE Valuation Cap and Discount: How Conversion Works. Accessed October 19, 2026.
- Terms.Law. SAFE Agreement Explained 2026: Valuation Cap vs Discount. Accessed October 19, 2026.
- ChopDawg. How Much Equity Should a Startup Founder Give Up? Accessed October 19, 2026.
- Cake Equity. Founder Equity, Founder Vesting, and Co-Founder Equity Split. Accessed October 19, 2026.