Free resource · For founders

SAFE Conversion Calculator

What your SAFE stack turns into when the priced round closes.

Jason Acevedo | Updated October 13, 2026

Founders tend to know what each SAFE cost in dollars and not what it will cost in ownership, because the answer depends on a round that has not happened yet. This calculator runs the conversion the way the post-money SAFE (the YC form in use since 2018) actually works: each SAFE converts at the lower of its cap price and its discounted round price, the option pool is topped up before the new money comes in, and everyone is diluted by the round. Enter what you have signed and the round you expect, and the cap table below updates as you type.

Nothing you enter is saved or sent anywhere. The numbers are a model, not a closing cap table; your counsel will run the real one from the documents.

The company today

Shares outstanding Founders, early employees, and options already granted Unallocated option pool (shares) Reserved but not yet granted. Zero if there is no pool Pool target after the round (%) What the term sheet asks for. 10% is common at Series A

The SAFEs

Post-money SAFEs. Leave the cap blank for an uncapped SAFE, the discount blank for no discount. A SAFE with neither converts at the round price.

#	Investor (optional)	Amount ($)	Post-money cap ($)	Discount (%)
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The priced round

Pre-money valuation ($) The headline number on the term sheet New money raised ($) Cash from the new investors, not counting the SAFEs

After the round

Enter the company, at least one SAFE, and the round to see the cap table.

Round price per share

Post-money valuation

Existing holders own

Cost of the SAFEs

points of ownership vs. no SAFEs

Holder	Converts at	Effective valuation	Shares	Ownership

How the math works

A post-money SAFE promises its holder a fixed slice of the company immediately before the new money comes in: amount divided by cap. A $500,000 SAFE at a $5 million post-money cap is 10% of the company at that moment, no matter how many other SAFEs are stacked beside it, which is why stacking SAFEs dilutes founders rather than the investors who came earlier. A discount SAFE instead converts at the round price less the discount, and a SAFE with both uses whichever gives the investor more shares. The option pool increase the new investors ask for also lands before their money, so it comes out of the existing holders and the SAFEs. Then everyone is diluted by the new money at the round price. The "cost of the SAFEs" figure runs the same round with no SAFEs at all and reports the difference.

What this does not model

Pre-money SAFEs (the form before late 2018), which use a different capitalization definition and dilute everyone including the SAFE holders as more are added. Convertible notes with accrued interest. Most-favored-nation side letters that upgrade an earlier SAFE's terms. Pro rata rights, which are a separate letter and change the next round rather than this one. If any of those are in your stack, the answer is close but not exact, and it is worth a conversation.

Where to go next

If the result surprised you, Cap Table Mastery explains the stacking problem in more detail and Do I Need a Lawyer for a SAFE? covers when a SAFE's terms need review. The SAFE vs. Priced Round framework helps with the decision before you sign the next one, and the Cap Table Audit Checklist is the cleanup list before the round that triggers all of this.

This calculator is general information, not legal advice, and using it does not create an attorney-client relationship. It models the standard post-money SAFE; your documents control. If you want the real pro forma run from your signed SAFEs, get in touch.