Fully diluted shares count every share that could exist if all options, warrants, convertible notes, SAFEs, and the unissued option pool converted into stock, not just the shares outstanding today.
Key takeaways
Fully diluted shares count every share that could exist if all options, warrants, convertible notes, SAFEs, and the unissued option pool converted into stock, not just the shares outstanding today. It's the denominator investors use to calculate real ownership percentages and price per share, because it captures future dilution already baked into the cap table.
Your ownership on a fully diluted basis is almost always lower than it looks from shares outstanding, because the option pool and outstanding convertibles all count. Investors price rounds off the fully diluted number, and expanding the option pool pre-money dilutes founders, not new investors. Always run your percentages fully diluted before you sign anything.