SAFE Note Dilution Calculator

A SAFE (Simple Agreement for Future Equity) is the most common early-stage fundraising instrument. It's a promise of future equity that converts at the next priced round.

This calculator handles the four key terms:

• Investment amount — what the investor puts in.
• Valuation cap — the maximum valuation at which the SAFE will convert.
• Discount — a percentage discount on the next-round price (typical: 15–25%).
• Post-money vs pre-money SAFE — the post-money version (YC 2018+) is much more dilutive to founders.

At conversion, the investor gets whichever is more favorable — valuation cap or discount.

Most founders dramatically underestimate SAFE dilution. With a $250K SAFE on an $8M cap, founders typically expect ~3% dilution. The actual answer depends on whether it's a post-money or pre-money SAFE, and how many other SAFEs exist.

Post-money SAFEs are stackable in a way that surprises founders: each new SAFE comes out of the founder's stake, not the existing SAFE holders. Five $200K SAFEs at $10M cap = ~10% dilution from SAFEs alone, before the priced round happens.

Run this calculator before signing any SAFE. If the result surprises you, your terms are too aggressive — renegotiate the cap or discount.