Educational estimates onlyNot financial or legal advice. Consult a startup attorney.
SAFE & convertible note worksheet

SAFE note dilution calculator

Stack multiple SAFEs at different caps, discounts, and types. See what each one converts to at the priced round and what your post-conversion ownership looks like with every SAFE folded in at once.

Form: ED-2Updated: 2026-04Data: YC SAFE v1.4
Form ED-2 / SAFE Stacking Worksheet

SAFE conversion at a priced round

$
$
1
$
$
%
Conv. price $0.8000Shares 312,500Owns 2.2%
2
$
$
%
Conv. price $1.20Shares 416,667Owns 3.0%
3
$
$
%
Conv. price $1.80Shares 416,667Owns 3.0%
§Pre-money SAFE

Cap is on the company before the priced round

The investor's ownership depends on how much else gets raised before they convert. Friendlier to founders if more capital flows in; punishing to them if the round is small. Mostly displaced by post-money SAFEs since 2018.

§Post-money SAFE

Cap locks investor ownership at conversion

The standard YC form since 2018. The cap is on the company after the SAFE money is in. Each later SAFE and the priced round dilute founders only, never previous SAFE holders. Easier for investors to model; more painful for founders to stack.

§Worked example

Three SAFEs into a Series A

A founder team with 10M shares raises $250K at a $8M post cap, then $500K at $12M, then $750K at $18M. They close a Series A at $25M pre-money raising $7M. The first SAFE converts at the $8M cap (lowest price), giving roughly 3.1% of post-Series-A ownership. The second converts at the $12M cap, taking another 4.2%. The third converts at $18M, taking 4.2% more. The Series A investor takes 21.9%. Founders, who started owning 100%, end with 66.6% retained. The same Series A without prior SAFEs would leave them at 78.1%.

§FAQ

SAFE FAQ

Each SAFE converts at the lowest of the round price, the round price discounted by the SAFE's discount rate, or the cap-implied price (cap divided by fully diluted shares before conversion). Whichever is lowest wins. Post-money SAFEs lock in a guaranteed ownership percentage at the cap; pre-money SAFEs do not.

Updated 2026-04-28