business · 2026-05-01

Founder equity dilution calculator

Project founder equity ownership through multiple funding rounds — pre-money, post-money, option pool refresh, and dilution per round.

Post-round founder ownership
47.6%

Inputs

Pre-money valuation$30,000,000
Investment amount$8,000,000
Target option pool post-round %12%
Current founder ownership %65%
Current option pool %8%

Supporting metrics

Dilution this round17.4%
Post-money valuation$38,000,000
Option pool refresh added7.2%

About this calculator

Founder dilution — the round-by-round math

Every priced funding round dilutes founders by:

  1. Investor ownership = investment ÷ post-money valuation
  2. Option pool refresh = additional pool created pre-money to reach target post-money pool
  3. Combined = founder loses (investor% + pool refresh% × (1 - investor%))

The pre-money pool refresh trick

VCs require a target option pool (10-15% post-round). If the current pool is smaller, the refresh comes out of pre-money — meaning EXISTING shareholders (founders) take the dilution from the pool refresh, not the new investors. This is standard but worth understanding.

Default scenario: $30M pre / $8M invest / 12% pool target → founder dilutes ~21% of their stake. A 65% owner becomes ~51%.

The compounding math

Each round multiplicatively dilutes:

Founders end at: 100% × (1 − 0.20) × (1 − 0.25) × (1 − 0.18) × (1 − 0.12) = ~43% combined founders.

Defenses

FAQ

What's the difference between pre-money and post-money pool?

Pre-money pool: shares created BEFORE the investor invests, dilutes existing shareholders only. Post-money pool: shares created AFTER, dilutes everyone proportionally including new investor. VCs always want pre-money for negotiating leverage. Founders should push for post-money — material difference at scale.

Should I take a higher valuation with more dilution?

Sometimes — depends on growth runway. $5M raise at $20M pre = 20% dilution. $10M raise at $50M pre = 17% dilution but 2× cash. The cash gives more time to grow before next round. Often math favors more capital + slightly more dilution if confident in execution.

What's a 'recap' and why is it dangerous?

A recap happens in down rounds where the new round price is below previous round price. Triggers anti-dilution adjustments that often dilute founders heavily. Most common: full ratchet (worst for founders) or weighted-average (much friendlier). Always insist on weighted-average anti-dilution at term sheet.