Investor Equity Calculator
Estimate how much ownership an investor receives based on the investment amount, pre-money valuation, and option pool changes.
Overview
Use this Investor Equity Calculator to estimate how much ownership an investor may receive in a funding round. Enter the investment amount, pre-money valuation, current founder ownership, and option pool assumptions to see the post-money valuation and likely dilution.
How it works
The calculator first adds the new investment to the pre-money valuation to get the post-money valuation. It then estimates investor ownership by dividing the investment amount by the post-money valuation. After that, it reserves the target post-money option pool and allocates the remaining ownership across existing holders in proportion to the current ownership percentages entered. This gives a simplified view of founder ownership after dilution.
How to use this calculator
- 1Enter the amount being invested.
- 2Add the agreed pre-money valuation.
- 3Enter the founders' current ownership percentage.
- 4Enter the current option pool percentage.
- 5Set the target option pool percentage after the round.
- 6Review the investor stake, post-money valuation, and founder dilution estimate.
Example Calculation
Investment amount
$500,000
Pre-money valuation
$2,000,000
Founder ownership before round
100%
Current option pool
0%
Target option pool after round
10%
Investor ownership
20.00%
With a $500,000 investment on a $2,000,000 pre-money valuation, the post-money valuation is $2,500,000 and the investor receives 20.00%. If a 10% post-money option pool is set aside, founder ownership is estimated at 70.00%.
Frequently asked questions
What does an investor equity calculator estimate?
It estimates the investor's ownership percentage, post-money valuation, and the effect of dilution on existing shareholders.
What is pre-money valuation?
Pre-money valuation is the agreed value of the company before the new investment is added.
What is post-money valuation?
Post-money valuation is the pre-money valuation plus the new investment amount.
How is investor ownership calculated?
In a simple priced round, investor ownership is usually the investment amount divided by the post-money valuation.
Why does the option pool affect founder ownership?
If the option pool is increased as part of the round, that additional pool usually dilutes existing shareholders unless negotiated differently.
Does this calculator handle SAFEs, convertible notes, or liquidation preferences?
No. This is a simplified equity estimate and does not model complex financing terms or multiple security types.
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Assumptions and warnings
Assumptions
- The investment is priced using the pre-money valuation entered.
- Percentages are treated on a fully diluted basis for a simplified estimate.
- If the target option pool is larger than the current pool, the calculator treats the difference as additional dilution.
- Founder ownership is estimated in proportion to the pre-round ownership you entered.
- Results are estimates and do not include legal terms, liquidation preferences, SAFEs, notes, or multiple share classes.
Warnings
- This calculator provides an estimate only and is not legal, tax, or financial advice.
- Equity outcomes can vary based on term sheets, cap table structure, and how option pool increases are negotiated.
- Review funding terms with a qualified lawyer or advisor before finalizing an investment round.