Cap Table Dilution Calculator
Calculate founder dilution across a funding round including an option pool.
About Cap Table Dilution Calculator
Dilution compounds multiplicatively across the option pool and the new investment. Whether the pool comes from pre-money materially changes who bears its cost, which is why it is a negotiated point. The option pool shuffle is often overlooked, yet a ten per cent pre-money pool costs founders more than a two point increase in the investor's stake.
Formula
Cap Table Dilution
Post-round ownership = current × (1 − pool dilution) × (1 − investor share)
- post-money valuation
- Pre-money plus the new investment
- pool shuffle
- Creating the pool pre-money dilutes existing holders rather than the new investor
Worked example
With the default values below, Cap Table Dilution Calculator returns Your Ownership After the Round of 28.800%. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Your current ownershipaccepts 0–100 %
- 40 %
- Pre-money valuationminimum 0.01
- 8,000,000
- New investmentminimum 0
- 2,000,000
- New option pool createdaccepts 0–30 %
- 10 %
- Option pool taken from pre-moneyone of Yes, No
- Yes
Results
- Your Ownership After the Round
- 28.800%
- Dilution Suffered
- 11.200%
- Post-Money Valuation
- $10,000,000.00
- Investor Ownership
- 20.000%
- Value of Your Stake
- $2,880,000.00
Step by step
- 1Values used
- 2Cap Table Dilution
- 3Your Ownership After the Round= 28.800
- 4Dilution Suffered= 11.200
- 5Post-Money Valuation= 10,000,000.00
- 6Investor Ownership= 20.000
- 7Value of Your Stake= 2,880,000.00
Assumptions and limits
- The result is derived only from the 5 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
- Figures are rounded for display to 3 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
- This is an estimate for general information and not professional financial, tax or legal advice. See the full disclaimer for the limits that apply to this kind of calculator.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
Frequently Asked Questions
How is Cap Table Dilution calculated?
Post-round ownership = current × (1 − pool dilution) × (1 − investor share) Dilution compounds multiplicatively across the option pool and the new investment. Whether the pool comes from pre-money materially changes who bears its cost, which is why it is a negotiated point.
Why does Cap Table Dilution matter?
The option pool shuffle is often overlooked, yet a ten per cent pre-money pool costs founders more than a two point increase in the investor's stake.
What values do I need to enter?
This calculator takes 5 inputs: Your current ownership, Pre-money valuation, New investment, New option pool created, Option pool taken from pre-money. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.