VC Funding Dilution Calculator

Calculate post-money dilution from VC round, option pool top-up, anti-dilution. Pre vs post-money math.

Post-Money
Investor %
Founder Post
Pre-money
Round size
Post-money
New investor stake
ESOP top-up dilution
Founder post-round
ESOP post-round
Ad Space

VC funding rounds dilute existing shareholders. The math: post-money = pre-money + raise. New investor stake = raise / post-money. ESOP top-up dilutes ONLY pre-money holders (founder, existing). Standard term-sheet structure.

Pre-Money vs Post-Money

Pre-money valuation = before the new investment. Post-money = after. Post-money = pre-money + raise. Investor stake = raise / post-money. A $20M pre + $5M raise = $25M post, 20% investor stake.

ESOP Top-Up Mechanics

VCs typically require ESOP pool brought to 10-15% post-money. Top-up shares come from pre-money (founders + existing dilute), not from new investor's stake. Negotiate the top-up size carefully — every 1% top-up = 1% founder dilution.

Anti-Dilution Protection

Investors often get weighted-average or full-ratchet anti-dilution. If next round prices lower (down round), investor's conversion ratio adjusts to give them more shares retroactively. Founders lose more in down rounds than just the new dilution.

Liquidation Preferences

1× non-participating standard. Participating preferred = double-dip (preference + share of remaining). Multiple preferences (2-3×) appear in later/down rounds. Affects exit returns, not ownership %, but reshapes payouts dramatically.

Last updated May 2026. Sources: Carta Cap Table Guide, NVCA Model Documents.