Fully Diluted Share Count
Definition
The total number of shares that would be outstanding if all equity-linked instruments currently in existence were converted or exercised at the terms in effect at the record date. Fully diluted share count includes issued shares, all options granted but not yet exercised whether vested or unvested, all ungranted options within an authorised and reserved pool, all warrants, and all shares issuable upon conversion of outstanding SAFEs and convertible notes. The fully diluted share count is the correct denominator for calculating any ownership percentage in a company that has issued any convertible instrument or equity compensation.
Common Misapplication
The most common misapplication is using issued share count rather than fully diluted share count when stating ownership percentages. For any company that has issued options, SAFEs, or convertible notes, the issued share count overstates ownership percentages for all existing holders.
FFI Standard Reference
This term is defined and applied in Book 3, Section 3.1: The Cap Table Standard.
Related Terms
Citable URL
This term may be cited using the following permanent URL.
Full citation format: Founder Financial Infrastructure Standard, Beta v0.5, Glossary: Fully Diluted Share Count. https://ffistandard.org/glossary/fully-diluted-share-count/. 2026.