Dilution Calculator

What is Dilution Calculator?

Dilution measures how much your ownership percentage decreases when new shares are issued during a funding round. If you own 50% of a company and raise a round that creates new shares equal to existing shares, your ownership dilutes to 25%.

How to use this calculator

1. 1Enter your current cap table: founder shares, existing investor shares, and option pool size.
2. 2Input the new investment amount and the pre-money valuation for the round.
3. 3Adjust the option pool top-up percentage that will be required before the round closes.
4. 4Review the pre- and post-money ownership percentages for each shareholder class.
5. 5Run the model across multiple future rounds to see your projected ownership at each stage.

Why this matters for founders

Every fundraise reduces your slice of the pie. Understanding dilution across multiple rounds helps you plan how much equity you will retain at exit. Founders who do not model dilution often discover they own far less than expected after several rounds.