SAFEs — Simple Agreements for Future Equity — are the most common fundraising instrument for pre-seed and seed-stage startups. Introduced by Y Combinator in 2013, SAFEs replaced convertible notes as the default early-stage fundraising tool because they are simpler: no interest, no maturity date, no debt on the balance sheet.
But simpler does not mean harmless. Founders who raise multiple SAFEs without modeling the cap table impact often discover at their Series A that they have given away significantly more equity than they expected. This guide explains how SAFEs work on your cap table, how they convert, and how to model dilution before you sign.
How SAFEs Sit on the Cap Table
A SAFE is not equity. It is a contractual right to receive equity in a future priced round. Until conversion, a SAFE does not appear as shares on the cap table — but it represents a claim on future shares that must be accounted for.
Think of SAFEs as reservations. You have not issued the shares yet, but you have committed to issuing them when a triggering event occurs. The triggering event is typically a priced equity round (Series Seed or Series A), a change of control (acquisition), or dissolution of the company.
For cap table management purposes, you should track every outstanding SAFE with the following details: investor name, investment amount, valuation cap (if any), discount rate (if any), and whether it is a pre-money or post-money SAFE. This last distinction — pre-money vs. post-money — materially changes how conversion works.
Pre-Money SAFEs vs. Post-Money SAFEs
The original SAFE (pre-2018) was a pre-money SAFE. In 2018, Y Combinator introduced the post-money SAFE, which is now the default.
The difference is in how the valuation cap is applied. With a pre-money SAFE, the valuation cap applies to the company's pre-money valuation at the time of conversion. The SAFE investor's ownership is calculated based on the pre-money cap, and then the new round's investment is added on top. Because the option pool and other SAFEs are not included in the cap, founders typically end up with slightly more ownership than they expected.
With a post-money SAFE, the valuation cap includes the SAFE itself (and all other SAFEs and options) in the ownership calculation. This means the dilution from the SAFE is more transparent and predictable — but also typically larger. The post-money SAFE gives the investor a known ownership percentage at conversion, regardless of how many other SAFEs are outstanding.
For founders, the key takeaway is: post-money SAFEs dilute more predictably but often more aggressively than pre-money SAFEs. Know which type you are signing.
How SAFEs Convert at a Priced Round
When a triggering event occurs — typically a Series A — all outstanding SAFEs convert to equity simultaneously. The conversion mechanics work as follows.
For each SAFE, the conversion price is the lower of: the valuation cap divided by the company's capitalization (pre-money or post-money, depending on the SAFE type), or the price per share of the new round minus the discount rate.
The SAFE investor receives shares at whichever price is lower — meaning whichever method gives them more shares. If a SAFE has both a valuation cap and a discount rate, both are calculated and the more favorable one (for the investor) applies.
The resulting shares are typically issued as preferred stock of the same series as the new round, or as a separate series of "shadow preferred" stock with the same economic terms.
The Stacking Problem — Multiple SAFEs With Different Terms
The real complexity arises when a founder has signed multiple SAFEs with different valuation caps and different discount rates. Each SAFE converts independently according to its own terms, and the aggregate dilution can be much larger than founders expect.
For example, consider a founder who raises three SAFEs: $500K at a $5M post-money cap, $300K at a $4M post-money cap, and $200K at a $6M post-money cap with a 20% discount. At a Series A with a $10M pre-money valuation, each SAFE converts at its own price, and the combined dilution from all three could exceed 20% before the Series A investor's shares are even issued.
The solution is simple but often skipped: model every conversion scenario before you sign each new SAFE. Use your cap table tool to run the math. DealCycl's scenario modeling lets you compare up to 5 conversion scenarios side by side, including different Series A valuations and multiple SAFE instruments.
Practical Rules for Managing SAFEs on Your Cap Table
Track every SAFE from the moment it is signed — do not wait for conversion. Model the conversion impact at multiple priced round valuations before signing each new SAFE. Know whether you are signing pre-money or post-money SAFEs. Keep the total number of outstanding SAFEs manageable — every new SAFE adds a conversion variable. And use a cap table tool that supports SAFE modeling natively, not a spreadsheet that requires manual formulas.
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