How venture works
Round sizes and dilution
Typical check sizes by stage, Carta's 2025 medians, and the algebra that 20% sold is 20% of everyone's stake.
Numbers below are orders of magnitude as of 2025–2026, drawn especially from Carta's State of Private Markets reporting. Your sector (AI infrastructure vs boring B2B), geography and market cycle will move you. Use medians to navigate, not to litigate a term sheet.
Concept
Pre-money is the negotiated company value before the new cash. Post-money = pre-money + new cash (simplified; option-pool shuffle complicates this — see priced rounds). Dilution ≈ new money / post-money for a clean primary round.
The big idea
Carta's Q1 2025 State of Private Markets put median seed pre-money around $16M and median Series A pre-money around $48M, with deal counts down year-over-year even as valuations for companies that cleared the bar rose. Dilution in that quarter was about 18.8% median at seed and 17.9% median at Series A — slightly below the long-running rule of thumb that each primary round sells roughly 15–25% of the company.
Later Carta commentary on early-stage markets (through late 2025) described seed and Series A post-money medians climbing further (seed post-money into the low-to-mid $20Ms; Series A post-money much higher), with dilution still clustering near ~19–20% while check sizes grew — the algebra of "similar dilution × larger rounds ⇒ higher prices."
Rough planning ranges founders still use in conversation (verify against current Carta/PitchBook before you negotiate):
| Stage | Round size (order of magnitude) | Dilution (primary) |
|---|---|---|
| Pre-seed | $250k–$2M (often SAFEs) | Highly variable; stack carefully |
| Seed | ~$2–6M+ | ~15–25% |
| Series A | ~$8–25M+ | ~15–25% |
| Series B | tens of millions | often teens % |
| Later | very wide | can compress for winners |
AI and "hot" categories sit above these medians; unfashionable B2B sits below. Pre-seed is frequently a pile of SAFEs rather than a priced round.
Walking through two rounds
Seed: raise $4M at $16M pre ⇒ $20M post ⇒ investors own 4/20 = 20%.
Series A: raise $15M at $60M pre ⇒ $75M post ⇒ new investors own 15/75 = 20%.
Prior shareholders (founders, employees, seed) are diluted by 20% of their stake — a founder at 40% after seed lands at 40% × 0.80 = 32% after A, before option-pool top-ups.
Common mistakes
- Treating a 2025 median as a promise to your deck. It is a weather report.
- Forgetting the pool shuffle. Pre-money pool top-ups take from existing holders, not from the new money.
- Stacking pre-seed SAFEs until "highly variable" becomes a conversion shock.
Check yourself
You raise $4M at $16M pre. What % do new investors own, and what is post-money?
$20M post-money; 4 / 20 = 20%.
A founder owns 40% after seed. Series A sells 20% with no other changes. What does the founder own?
40% × 0.80 = 32%.
Key takeaways
- Primary rounds commonly sell ~15–25%; Carta's 2025 medians sat near the high teens for seed and A.
- Dilution ≈ new money / post-money on a clean primary round.
- Similar dilution times larger checks means higher prices — that is the 2025 algebra.
- Use current Carta/PitchBook ranges; AI and cycles move numbers fast.
Further learning
Carta: State of Private Marketscarta.comNext, what investors need to see: round milestones.