Cap Table Calculator

What is a cap table?

The cap table calculator above converts raw share counts into ownership percentages across the three groups that appear on almost every early-stage capitalization table: founders, investors, and the employee option pool. A capitalization table — “cap table” for short — is the single source of truth for who owns what in a company. Every share, every percentage, every stakeholder is tracked here, and it is the document investors scrutinize first during any financing or acquisition.

At its core, a cap table answers one question: if the company were sold today, how would the proceeds be split? That split is determined entirely by each party’s percentage of the fully-diluted shares outstanding. Founders who understand their cap table can reason clearly about dilution, option pool sizing, and what their stake is actually worth. Founders who don’t are often surprised by how the math works out at exit.

The formula

Total shares     = Founder shares + Investor shares + Option pool shares
Founder %        = Founder shares / Total shares
Investor %       = Investor shares / Total shares
Option pool %    = Option pool shares / Total shares

Each group’s ownership is simply its share count divided by the total fully-diluted shares outstanding. “Fully-diluted” means counting all shares that could exist — including the entire option pool, whether or not those options have been granted or exercised yet. This is the conservative, standard way investors evaluate ownership, because it reflects the maximum possible dilution.

Worked example

A typical early-stage cap table after a seed round might look like this:

• Founder shares: 8,000,000
• Investor shares: 1,500,000
• Option pool shares: 500,000

Total = 8,000,000 + 1,500,000 + 500,000 = 10,000,000
Founder %     = 8,000,000 / 10,000,000 = 80%
Investor %    = 1,500,000 / 10,000,000 = 15%
Option pool % = 500,000 / 10,000,000 = 5%

The founders hold 80%, investors 15%, and 5% is reserved for employees. Note that the option pool counts against everyone’s ownership even before a single option is granted — because it is part of the fully-diluted total. This is why the size of the option pool is a negotiated term: a larger pool dilutes founders more.

What happens if the option pool is expanded to 1,500,000 shares to fund hiring?

Total = 8,000,000 + 1,500,000 + 1,500,000 = 11,000,000
Founder %     = 8,000,000 / 11,000,000 = 72.7%
Investor %    = 1,500,000 / 11,000,000 = 13.6%
Option pool % = 1,500,000 / 11,000,000 = 13.6%

Expanding the pool diluted everyone — the founders dropped from 80% to 72.7%. When a pool expansion is required as a condition of a financing and carved out of the pre-money valuation, that dilution falls disproportionately on founders. This is the well-known “option pool shuffle.”

Benchmarks

Common starting points for an early-stage cap table:

• Founders: typically own 60–80% after a seed round, declining with each subsequent raise.
• Option pool: commonly sized at 10–20% of fully-diluted shares to cover hires until the next round. Investors often push for the pool to be created (or expanded) before they invest.
• Investors: 15–25% per priced round is the standard range.

Across multiple rounds, founder ownership commonly lands somewhere between 15% and 40% by the time of a meaningful exit, depending on how many rounds were raised and at what valuations.

How to interpret and use it

The most important habit a cap table builds is thinking in fully-diluted terms. A founder who believes they own “85% because that’s how many shares I have out of the issued total” is fooling themselves if a large option pool is authorized but ungranted — the diluted number is what matters at exit.

The second habit is modeling the option pool deliberately. The pool is real dilution, so size it to your actual hiring plan rather than accepting an arbitrarily large pool. An oversized pool authorized before a round means founders absorb dilution for equity that may never be granted.

This calculator handles the three-group case that covers most pre-Series-A companies. For companies with multiple investor classes, convertible notes, SAFEs, warrants, and several financing rounds, a full cap table modeling tool (or a spreadsheet with a row per security) is needed to track liquidation preferences and conversion mechanics — but the underlying math is always the same: each holder’s percentage equals their shares over the fully-diluted total.

Frequently asked questions

What is a cap table? A capitalization table (cap table) lists who owns what in a company. It tracks every shareholder — founders, investors, and the employee option pool — and the percentage of the company each one holds.

How is ownership percentage calculated? Each stakeholder’s ownership equals their share count divided by the total fully-diluted shares outstanding (the sum of all share counts), expressed as a percentage.