Pre-money vs Post-money Valuation Calculator
Convert between pre-money and post-money valuation and estimate investor ownership from a financing round size.
Pre-money valuation is the company value before the new investment. Post-money valuation is pre-money plus the new investment (simplified).
Investor ownership in a new round is typically approximated as investment / post-money (ignoring option pool changes and other instruments).
Prefer an explanation- Read the guide.
Pre-money vs post-money valuation: formulas, ownership, and pitfallsFundraising & valuation hub: pre/post-money, SAFEs, notes, and liquidation prefsOption pool shuffle: how it impacts founder dilution (with example)Pro rata rights: what they mean and how to estimate your check size
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Tip: you can type commas (e.g., 10,000).
Example
Using the default inputs, the result is:
20%
- Pre-money valuation
- $20,000,000
- New investment
- $5,000,000
How to calculate
- Enter pre-money valuation.
- Enter new investment amount (round size).
- Review post-money valuation and implied investor ownership.
Formula
Post-money = pre-money + investment; investor % ~ investment / post-money
- Simplified equity financing model; ignores option pool changes, SAFEs/notes, and fees.
- Uses valuation-based ownership approximation rather than a full cap table.
FAQ
Is investor ownership always investment / post-money-
Often as a first approximation, yes. But option pool increases, SAFEs/notes converting, and share-class terms can change the final ownership.
What is the option pool shuffle-
It's when the option pool is increased before the investment and counted in the pre-money, which dilutes existing shareholders more than the simple investment / post-money calculation suggests.
Common mistakes
- Ignoring option pool increases (the option pool shuffle changes effective founder dilution).
- Mixing enterprise value (EV) and equity value concepts (this is an equity financing simplification).
- Assuming the implied ownership is exact (term sheet details matter).
How to interpret
Valuation tips
- Use post-money for quick ownership math, but validate with a cap table model.
- Model the option pool shuffle explicitly if you're negotiating founder dilution.
- Keep definitions consistent (pre-money, post-money, fully diluted shares).
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Quick checks
- Use consistent time units (monthly vs annual) when entering rates and cash flows.
- Run a sensitivity check on the input that drives the result most (often discount rate or growth).
- Treat the output as a decision aid, not a prediction; validate assumptions with reality.