Pre-Money vs. Post-Money Valuation

Pre-money valuation is what investors agree a startup is worth before new investment; post-money is the value after — the difference is the amount raised, and it directly determines what percentage of the company investors receive.

When a startup raises a funding round, two numbers are fundamental to the deal: the pre-money valuation and the post-money valuation. The pre-money valuation is the agreed-upon value of the company immediately before new investment arrives. The post-money valuation is the pre-money valuation plus the new investment amount. The investor's ownership percentage is their investment divided by the post-money valuation. These two numbers determine everything about the economics of a funding round — and they directly affect how much every existing shareholder (including employees with options) is diluted.

The math is simple: if a company is valued at $9M pre-money and raises $3M, the post-money valuation is $12M. The investor owns $3M / $12M = 25% of the company. All existing shareholders — founders, early employees, SAFE and convertible note holders — collectively own the remaining 75%. If an employee held 1% of the company before this round, she now holds 1% × 75% = 0.75% — she's been diluted by 25%. Her percentage dropped, but if the company is genuinely worth $12M post-money, the absolute value of her 0.75% ($90,000) may be more than her 1% was worth before the round if the company was previously worth less than $9M.

The pre/post-money distinction also determines where the option pool expansion falls. Investors typically require that the employee option pool be set at a target size (e.g., 15–20% of the post-round cap table) before they price their investment. If the pool is too small, it must be expanded — and that expansion happens pre-money, meaning the dilution from creating new option pool shares falls on existing shareholders before investors calculate their ownership. A $9M pre-money valuation with a required 15% option pool expansion built in means founders and early employees absorb that dilution first. This is why sophisticated founders negotiate for post-money option pools — if investors agreed to include the pool in post-money, they'd share in the dilution.

For employees evaluating startup equity offers, the pre/post-money distinction matters in two ways. First, when your offer says you're receiving '0.5% of the company,' that percentage is typically calculated on a fully diluted post-money basis — after all outstanding shares, options, warrants, SAFEs, and convertible notes are included. A 0.5% grant on a $20M post-money cap table means roughly $100,000 in theoretical current value (before any probability discounting for startup risk). Second, every future round will dilute that percentage — modeling expected dilution through future rounds (typically 20–25% per round) gives a more realistic picture of what your equity might ultimately represent.

The Dilution Math

  • Pre-money valuation: $18M. New investment: $6M. Post-money: $24M. Investor ownership: $6M / $24M = 25%.
  • All existing shareholders are diluted by 25%: a 2% pre-round stake becomes 2% × 75% = 1.5% post-round.
  • Multiple rounds compound: 2% at seed → ~1.5% after Series A → ~1.1% after Series B → ~0.85% after Series C. The percentage keeps shrinking; the value depends on whether the valuation grows faster.
  • The option pool shuffle: if investors require a 15% post-round option pool and it needs to be expanded from 10%, the 5% expansion dilutes pre-money shareholders — not the investors. This is negotiable but rarely negotiated successfully by founders.
  • Fully diluted share count: always evaluate your ownership percentage on a fully diluted basis — including all outstanding options (vested and unvested), warrants, SAFEs, and convertible notes that will become shares.

Why This Matters for Your Equity Offer

  • Your percentage in the offer letter is a snapshot of the current cap table — it will be diluted by every future round.
  • Model three to five years of dilution: if the company raises two more rounds before exit, your percentage may be half of what it was at grant. Is the exit valuation likely to compensate?
  • The post-money SAFE overhang: post-money SAFEs lock in investor ownership before a priced round, which means that ownership directly dilutes founders and employees — know how much is outstanding.
  • Valuation ≠ liquidity: a $100M post-money valuation is theoretical. Your equity is worth that percentage of $100M only if the company exits at or above that value, after accounting for liquidation preferences and other senior claims.
  • Ask for a cap table: any serious startup can provide a fully diluted cap table. If they won't share it with a senior hire, that's a red flag.

Example

An engineer is joining a Series A startup and receives an offer for 50,000 options with a $1.00 strike price. The company says there are 10,000,000 shares fully diluted, making her grant 0.5%. The Series A raised $10M at a $30M pre-money / $40M post-money valuation — so the company's current theoretical value is $40M. Her 0.5% is theoretically worth $200,000 today. But she models the future: the company will likely raise a Series B (dilutes ~20%) and possibly a Series C (dilutes another ~20%). After those rounds her 0.5% becomes roughly 0.32%. If the company exits at $200M — a 5x increase from today's value — her stake is worth 0.32% × $200M = $640,000 pre-tax, minus her strike cost of $50,000. If the company exits at $40M (flat from today's value), she makes $128,000 − $50,000 = $78,000 — hardly the lottery ticket early hires imagine. The pre/post-money math is the foundation of understanding whether startup equity is actually worth the risk.