SAFE Conversion Math: Valuation Caps, Discounts and Ownership

A Simple Agreement for Future Equity (SAFE) gives an investor a contractual right to receive equity on a later financing or another event defined in the agreement. Calculating the conversion requires the exact SAFE form, its cap or discount, the defined capitalization and the terms of the priced round.

Y Combinator's current SAFE forms and user guide distinguish post-money valuation-cap SAFEs, discount-only SAFEs and most-favored-nation (MFN) forms. The terms of an executed contract control the actual calculation.

Start by identifying the type of SAFE

A post-money valuation-cap SAFE expresses the investor's pre-new-money ownership target more directly than an older pre-money SAFE. A discount SAFE instead uses a reduced per-share price relative to the next qualifying financing. An MFN provision has its own election mechanics. Treat separate forms as separate cases.

Post-money valuation-cap example

Assume a single $500,000 post-money cap SAFE with a $10 million valuation cap. In the simplifying case described by YC's post-money framework, the investment amount divided by its cap indicates a 5% stake immediately before the new money in the next priced equity financing, subject to the SAFE's capitalization definition and exclusions.

Illustrative pre-new-money SAFE ownership = $500,000 ÷ $10,000,000 = 5%

The priced round can subsequently dilute that stake through new primary shares. An option-pool increase adopted as part of the financing may also affect the holder under the form's definitions. Calculate the fully diluted cap table rather than assuming 5% remains the final post-financing holding.

Discount-only SAFE example

Assume the next priced round is issued at $2.00 per share and the SAFE gives a 20% discount. The conversion price under that illustration is $1.60. If the SAFE purchase amount is $400,000 and the form supplies no other adjustment, that implies 250,000 conversion shares.

Discount conversion price = $2.00 × (1 − 20%) = $1.60; $400,000 ÷ $1.60 = 250,000 shares

The investor's ownership depends on the final fully diluted share denominator. A discount alone does not establish an ownership percentage when the size of the round and cap table have yet to be finalized.

What if both a cap and a discount are present?

Some negotiated instruments require comparison of cap-based and discounted prices. The economically more favorable conversion price may apply under the contract. A current YC standard form may instead use one mechanism, so the fund should inspect the signed instrument rather than assume a universal combined formula.

Which assumptions can change the result?

Multiple outstanding SAFEs, option pool increases, capitalization exclusions, new-money round pricing, convertible notes and side-letter rights can interact. The option pool guide and pre-money versus post-money explanation give related financing context.

YC's SAFE conversion calculator can help investors inspect common scenarios. The final model should reconcile to the signed agreements and the closing capitalization schedule, with counsel reviewing legal interpretation.

A conversion evidence checklist

Collect the executed SAFE and amendments, purchase amount, valuation cap or discount, capitalization schedule and proposed priced-round term sheet. Record the share class delivered on conversion, conversion date and any optional participation rights.

Treto's Diligence workspace can organize these documents and unanswered financing questions for team review. The conversion mathematics and issuance record remain with the responsible transaction professionals.

Questions investors ask

Does a $500,000 SAFE with a $10 million post-money cap mean exactly 5% after Series A?

The simple 5% result describes an ownership interest before new primary round dilution under the relevant post-money SAFE assumptions. Shares sold in a subsequent priced round and certain capitalization changes may reduce the eventual percentage. The actual SAFE terms and closing cap table determine it.

Is the valuation cap the valuation of the startup today?

A SAFE valuation cap is a contractual conversion term. It can establish a price used in a future financing under defined conditions and does not itself represent a negotiated priced-equity valuation or a guaranteed exit value.