Wait — what's a SAFE, and why does it shrink my ownership?
A SAFE is the most common way startups raise their first cheques. An investor gives you money now; in return they get shares later — automatically, when you do a real "priced" funding round. It's one page, easy to sign. So founders sign several.
Here's the catch. With the standard SAFE used today (the "post-money" SAFE), each investor's slice is locked in — they don't get diluted by the next SAFE, or by the new hires' stock options. Someone has to absorb all of that giving-away. That someone is you, the founder. Three "small" SAFEs can quietly cost you a quarter of your company before a big investor ever shows up. This tool makes that visible.
- Valuation cap
- The price ceiling on a SAFE. A lower cap = the investor gets more of your company. The most expensive thing you can sign.
- Discount
- A markdown (often 10–20%) that lets the SAFE investor buy in cheaper than the next round. The tool gives them whichever helps them more — cap or discount.
- Option pool
- Shares set aside for future employees. Your next big investor will make you create it before their money — so it comes out of your slice, not theirs.
- Priced round
- A "real" funding round at an agreed valuation (your Series A, usually). This is when every SAFE converts into actual shares — and the dilution lands.
Where you start today
The SAFEs you've signed
Your next funding round
If that number stung, that's the point.
Dilution isn't fixed — it's negotiated. The cap you accept, the pool you let them push before their money, the order you raise in: each is a lever, and most founders give them away without knowing. I've sat on the company side of these rounds. Before you sign the next SAFE or term sheet, get a second read.
Get a second read on your round →How the math works (for the curious)
The post-money SAFE rule. Each SAFE investor owns amount ÷ valuation cap of the company, measured just before your priced round. They're protected from your other SAFEs and from the new option pool — only the new round's money dilutes them. You, the founder, absorb everything else. That's the whole reason stacking SAFEs hurts.
Cap or discount — whichever helps them. Every SAFE converts at the lower of its cap price or its discount price, exactly as the contract says. The tool solves the whole cap table at once (the SAFE shares, the new pool, and the round price all depend on each other) and lands on the answer.
The option-pool shuffle. The new pool you enter is created before the new money — standard lead terms — so it dilutes you, not them. Push even half of it to after their money and you claw back real ownership. This tool lets you test that.
What it doesn't cover. Pre-money SAFEs, MFN clauses, pro-rata side letters, and convertible-note interest. It's a clear planning estimate to show the shape of your dilution — not your official cap table or a substitute for counsel.
An estimate for planning — not legal, tax, or financial advice. Real cap-table math depends on the exact terms of every document; check against your signed paperwork and your lawyer before you rely on it. Nothing leaves your browser. Logic current as of June 2026.