Fully diluted shares
What does fully diluted shares mean?
Fully diluted shares is the total number of shares that would be outstanding if every instrument convertible into or exercisable for equity were exercised or converted: issued common shares, issued preferred shares (on an as-converted basis), all options (vested and unvested), all warrants, all convertible notes (at their conversion price), and all SAFEs (at their conversion caps). It is the most comprehensive measure of company ownership and the denominator investors use to calculate any ownership percentage.
What is included in the fully diluted share count?
| Instrument | Included in fully diluted? |
|---|---|
| Issued common shares | Yes, always included |
| Issued preferred shares | Yes, included on an as-converted-to-common basis |
| Granted stock options (vested and unvested) | Yes, included even if unvested and unexercised |
| Ungranted option pool reserve | Yes, the full authorised pool, not just granted options |
| Convertible notes | Yes, included at their applicable conversion price |
| SAFEs | Yes, included at their conversion cap or discount, whichever produces more shares |
| Warrants | Yes, included at their exercise price |
Why does the fully diluted share count matter?
Ownership percentages mean nothing without specifying the denominator. A founder who owns 3,000,000 shares out of 10,000,000 issued shares appears to own 30%. But if there are 2,000,000 options outstanding plus 1,000,000 shares reserved in the option pool plus 2,000,000 SAFE conversion shares, the fully diluted count is 15,000,000. The founder's true ownership is 20%, not 30%. All investor term sheets and cap tables should be read on a fully diluted basis.
How do fully diluted shares affect price per share in a round?
Price per share in any funding round is calculated by dividing the post-money valuation by the fully diluted share count. A company with a $10M post-money valuation and 8,000,000 fully diluted shares has a price per share of $1.25. The same post-money with 12,000,000 fully diluted shares (because of a larger option pool or more convertible instruments) has a price per share of $0.83. The investor's ownership percentage is the same in both cases, but the per-share price affects option strike prices (set via 409A), secondary transaction pricing, and the calculation of liquidation preferences for existing preferred holders.
Why are treasury shares excluded from the fully diluted share count?
Treasury shares, shares previously issued and subsequently repurchased by the company, are authorised and issued but not outstanding. They are excluded from the fully diluted share count because they represent no economic claim on the company. Under Delaware General Corporation Law, companies can hold repurchased shares as treasury shares or cancel them; either way, they are excluded from the fully diluted count.
What do founders get wrong with fully diluted share calculations?
The most frequent error is quoting ownership percentages on an issued-and-outstanding basis rather than fully diluted. A founder who holds 40 percent of issued shares may actually own 28 percent on a fully diluted basis once options, warrants, SAFEs, and convertible notes are included. Presenting ownership to co-founders, employees, or prospective hires on a non-diluted basis sets up a difficult conversation when the cap table is fully revealed.
A second mistake is failing to include pro-forma fully diluted calculations in term sheet modelling. Founders often evaluate a new investment round based on pre-money valuation and percentage ownership of the new shares, without accounting for the full option pool refresh and unissued warrants that will be included in the fully diluted count at close. The actual post-money ownership for existing shareholders is almost always lower than the headline percentage suggests.
Third: not maintaining a live, accurate fully diluted cap table throughout the life of the company. SAFEs convert at variable valuations, convertible notes have variable discount rates, and option pools are refreshed at each round. A cap table that is only updated at fundraising events will almost certainly contain errors. Investors at every stage will request a fully diluted cap table as part of due diligence; a disorganised or inaccurate one signals poor financial governance and can delay a close.
How it works in practice
Case example: Issued vs fully diluted ownership in a fundraise
A startup has 8,000,000 issued common shares (founders) plus 1,000,000 preferred shares (seed investors). On an issued basis, the seed investors own 11.1% (1M / 9M total issued).
But the fully diluted cap table also includes: 1,500,000 granted options, 500,000 ungranted option pool reserve, 800,000 SAFE conversion shares (estimated). Fully diluted total: 11,800,000 shares.
Seed investor ownership on a fully diluted basis: 1,000,000 / 11,800,000 = 8.47%, not 11.1%. When the Series A investor sees the cap table, they calculate all ownership percentages on the fully diluted count. A founder who presents the non-diluted figure to investors creates a trust problem when the full diluted count is discovered in diligence.
Frequently asked questions
Should I always use fully diluted shares to calculate ownership?
Yes, for any purpose where the stake being discussed might be diluted by future conversions or exercises, which is essentially every material ownership discussion. Non-diluted share counts are rarely meaningful in a venture context.
Does the option pool affect fully diluted ownership before options are granted?
Yes. The total authorised option pool (including ungranted reserves) is included in the fully diluted count. This is why the option pool shuffle at fundraise affects founder dilution: the ungranted pool increases the fully diluted denominator before the investor's shares are even added.
How do SAFEs appear in the fully diluted cap table?
SAFEs are modelled at their conversion terms (cap or discount) and included in the fully diluted count as if converted at those terms. Before a priced round triggers conversion, SAFE shares are estimated based on the most likely conversion scenario.
What is the difference between fully diluted and fully diluted and as-converted?
They are the same concept. As-converted means all preferred shares are converted to common on a 1-for-1 basis (or at their conversion ratio). Fully diluted adds all warrants, options, and convertibles on top of the as-converted preferred count.
How do warrants affect the fully diluted share count?
Warrants are included in the fully diluted count at their exercise price, on an as-exercised basis (the same treatment as options). Warrants issued as part of venture debt or mezzanine financing deals are a common source of dilution that founders sometimes undercount. A $3M venture debt facility with warrants covering 2% equity can add a meaningful number of shares to the fully diluted count, reducing per-share price calculations for subsequent rounds.
Related glossary terms
- Option Pool, the equity reserve that is always included in fully diluted count even before options are granted
- Authorized Shares, the maximum share count within which the fully diluted count must always remain
- Post-Money Valuation, calculated by dividing the post-money by the fully diluted share count to get price per share
Explore related Fintera content
- How to Prepare Financials for a Series A Raise, where the fully diluted cap table is presented as part of Series A diligence
- Fractional CFO for Startups: The 2026 Playbook, how a fractional CFO maintains and presents the fully diluted cap table to investors
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