Founder Equity Dilution Calculator

Understand ownership after fundraising rounds. Calculate investor percentage, founder dilution, and simulate future ownership.

Calculator
Business
Finance
Startup

Single Round Dilution

Your current ownership before this round

Amount being raised in this round

Company valuation before new investment

How many co-founders share ownership

Equity reserved for future employee stock options

Multi-Round Simulation

Simulate your ownership across 3 typical funding rounds (Seed, Series A, Series B) using realistic valuation ranges and raise percentages. Uses your current ownership and option pool settings as the starting point.

About This Tool

The Founder Equity Dilution Calculator helps startup founders understand how their ownership changes through fundraising rounds. By modeling investment amounts, valuations, and option pools, you can forecast your equity position after each round and plan your fundraising strategy accordingly.

Understanding dilution is critical for founders. Each funding round introduces new investors and potentially expands the option pool, both of which reduce your percentage ownership. However, a smaller percentage of a larger pie is often worth more — the goal is to manage dilution strategically.

For evaluating what your startup might be worth, try our SaaS Valuation Calculator to estimate your company's value based on revenue and growth metrics.

If you are considering selling your startup, our SaaS Acquisition Value Calculator can help you estimate what your business could sell for.

Explore more tools in our Business tools collection.

Key Formulas:

Post-Money = Pre-Money + Investment Investor % = Investment ÷ Post-Money × 100 Founder New % = Current Ownership × (1 − Investor% ÷ 100) × (1 − Option Pool% ÷ 100)

The option pool dilutes all existing shareholders before new investors enter, so it is applied after calculating the investor's stake but before arriving at the final founder ownership.

Key Features:

  • Calculate investor ownership percentage and post-money valuation
  • See founder dilution including option pool impact
  • Generate a cap table showing all stakeholders
  • Simulate 3 funding rounds (Seed, Series A, Series B)
  • Split ownership across multiple co-founders
  • 100% browser-based — your financial data stays private

All calculations are performed in your browser. No data is sent to any server, ensuring your startup financial planning remains completely private.

Frequently Asked Questions (FAQ)

How does equity dilution work in fundraising?
Equity dilution happens when a company issues new shares to investors during a funding round. Existing shareholders (founders, employees, early investors) see their ownership percentage decrease because the total number of shares increases, even though the economic value of their stake may rise. Our tool calculates the impact of each round on founder ownership.
What is the difference between pre-money and post-money valuation?
Pre-money valuation is the company's value before receiving new investment. Post-money valuation is the pre-money valuation plus the new investment amount. For example, if a startup has a $8M pre-money valuation and raises $2M, the post-money valuation is $10M. The investor then owns 20% ($2M ÷ $10M) of the company.
How does the option pool affect founder dilution?
The option pool is equity reserved for future employees, typically 10-20%. It dilutes all existing shareholders, including founders. The pool is usually created or topped up before a funding round, meaning founders absorb this dilution before new investors come in. Our calculator accounts for this by applying option pool dilution to the post-investment founder stake.
Is my financial data secure?
Yes. All calculations happen entirely in your browser. No data is sent to any server. Your financial inputs and results remain completely private and are never stored externally.