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Equity Dilution Calculator

Enter your cap table, model up to three funding rounds with option pool top-ups, and see exactly what each holder owns before and after every round. Everything runs in your browser — nothing is uploaded.

post-money = pre-money + investment investor ownership = investment ÷ post-money pool top-up ownership = pool % of post-money (new shares reserved at close) new total shares = existing shares ÷ (1 − investor % − pool %) investor shares = investor % × new total shares pool shares = pool % × new total shares price per share = investment ÷ investor shares holder % after round = holder shares ÷ new total shares

About this tool

This calculator uses the standard venture math where the option pool top-up is created as part of the round and counted in the post-money fully diluted share count — the way most term sheets are written. That means the pool dilutes existing holders, not the new investor, which is why founders often end up owning less than a naive "investment ÷ post-money" estimate suggests. Every formula is printed above so you can audit the numbers by hand.

It is a modeling aid, not legal or financial advice: real rounds involve SAFEs, liquidation preferences, pro-rata rights, and conversion mechanics this simple model ignores. Your cap table never leaves the page — there is no server, no upload, and no tracking of tool inputs.

Found this useful? 113 free, browser-only tools by Yuvrajsinh Jadav — an engineer who ships production AI systems. No account, nothing sent anywhere.