VC & Startup Calculators

The term-sheet and fund math that actually decides outcomes — free, interactive, no signup. Definitions live in the VC glossary.

Dilution Calculator →

What a round really costs every existing holder — including the option-pool carve-out that lowers your effective pre-money.

SAFE Conversion Calculator →

Cap vs. discount: see exactly what a post-money SAFE converts into at the next priced round, and which term governs.

Fund Returner Calculator →

The math VCs run on every check — what exit value one position needs to pay back the entire fund.

The three pieces of startup math these calculators cover

Dilution: what a priced round costs every existing holder

Every priced round reduces existing ownership by the same ratio: sell 20% of the company and every current holder keeps 80% of their prior stake. The part most founders miss is the option pool. Investors almost always require the pool refresh to come out of the pre-money valuation, which means existing holders — not the new investor — absorb it. A founder at 60% who raises a round selling 20% with a 10% pool refresh doesn't drop to 48%; they drop further, and after two such rounds they typically sit near 43%. The dilution calculator runs the exact share math so the pool carve-out is never a surprise.

SAFE conversion: cap vs. discount, whichever prices lower

A SAFE converts at the next priced round using whichever of its two terms gives the investor the lower price per share: the valuation cap or the discount. Post-money SAFEs — the YC standard since 2018 — fix ownership at signing: $500K on a $5M post-money cap is exactly 10% of the company, locked in before the round even prices, and the founders absorb that dilution rather than the new lead. Stack several SAFEs and the combined bite is often larger than founders expect. The SAFE conversion calculator shows which term governs and what each SAFE turns into.

Fund-returner math: the arithmetic behind every VC pass

"Returning the fund" means one position pays back the fund's entire committed capital — a $100M fund needs a single investment to produce $100M in proceeds. The arithmetic is ownership × exit value: at 10% ownership at exit, the company must be worth $1B for that one position to return the fund. That single multiplication explains most confusing VC behavior — why funds target 10–20% ownership, fight for pro-rata, and pass on solid businesses with $100M ceilings. The fund returner calculator runs it for any fund size and check.

Frequently asked questions

How does startup dilution work?
Dilution is the reduction in your ownership percentage every time the company issues new shares. In a priced round, new-investor shares plus any option-pool refresh are added to the share count, so every existing holder's percentage shrinks by the same ratio. Selling 20% of the company in a round means every existing holder keeps 80% of their prior stake — a founder at 60% drops to 48% from that round alone.
How much equity do founders give up per round?
Typical dilution is 10–20% at pre-seed/seed, 15–25% at Series A, and 10–20% at Series B, plus a 10% option-pool refresh that usually comes out of the pre-money — meaning existing holders absorb it, not the new investor. A founder who starts at 60% after co-founder splits commonly lands around 40–45% after two priced rounds once pool refreshes are counted.
How does a SAFE convert to equity?
A SAFE converts into shares at the next priced round, at whichever of its two terms produces the lower price per share: the valuation cap or the discount. A post-money SAFE fixes the investor's minimum ownership at signing — $500K on a $5M post-money cap is 10% of the company, locked in before the round prices, with founders (not later investors) absorbing that dilution.
What does "return the fund" mean?
Returning the fund means a single investment generates proceeds equal to the fund's entire committed capital — for a $100M fund, one position producing $100M back. The math is ownership times exit value: if the fund owns 10% at exit, the company must be worth $1B for that position alone to return $100M. This is why VCs pass on good-but-modest outcomes; the model needs each check to have fund-returning potential.
How much of a startup does a VC need to own?
Most venture funds target 10–20% ownership at entry and try to defend around 10% at exit after later-round dilution. At 10% ownership, a $100M fund needs a $1B exit for one position to return the fund — which is the arithmetic behind ownership targets, pro-rata rights, and why funds fight for allocation rather than just picking winners.