Market Capitalization Calculator

What market cap measures

Market cap reflects the market's consensus valuation of a company's equity. It is used for index construction, portfolio allocation, and comparing companies by size.

Unlike enterprise value, market cap includes only equity value — it does not account for debt or cash on the balance sheet.

Because market cap changes whenever the share price changes, it is a current-market snapshot rather than a fixed measure of business value. Share splits do not change market cap by themselves because the lower price is offset by more shares; new issuance, buybacks, and real price moves do change the calculation.

Core formula

Multiply total shares by the current share price. For public-company analysis, the share count should usually come from the same reporting basis as the price date. Analysts often check diluted shares when options, restricted stock units, convertibles, or other potential equity claims could matter.

This calculator also estimates free-float market capitalization by applying the entered free-float percentage. Free-float market cap can matter for index eligibility, liquidity screens, and investability because it excludes shares that are closely held or otherwise not usually available to trade.

Cap-size classification

Mega-cap: over 200 billion. Large-cap: 10–200 billion. Mid-cap: 2–10 billion. Small-cap: 300 million–2 billion. Micro-cap: 50–300 million. Nano-cap: below 50 million. These thresholds are approximate and vary by source.

Worked example

A company has 50 million shares at 45 per share. Market cap = 50,000,000 × 45 = 2,250,000,000 (2.25 billion). Using the approximate size bands in this calculator, that is a mid-cap classification.

If 85% of those shares are considered free float, the free-float market cap is 1.9125 billion. If the same company has 300 million of debt and 120 million of cash, the simplified enterprise value estimate is 2.43 billion. That bridge helps explain why two companies with the same market capitalization can still have different business-value profiles.

Market cap vs free float vs enterprise value

Total market cap values the common equity. Free-float market cap narrows the figure to the portion of equity that is generally available for public trading. Enterprise value moves in the other direction: it starts with market cap, adds debt, and subtracts cash to approximate the value of the operating business across capital providers.

Those three figures answer different questions. Market cap is the standard company-size headline. Free float is more useful for trading, index weighting, and investability. Enterprise value is usually more useful when comparing valuation multiples such as EV/EBITDA because it adjusts for capital structure.

Limitations

Fluctuates with stock price. Does not reflect debt or cash unless you use the optional enterprise-value context fields. Free-float market cap depends on a user-entered free-float percentage and is only an approximation.

Cap-size labels are useful shorthand, not investment recommendations. A mega-cap can be overvalued, a small-cap can be financially strong, and a micro-cap can carry liquidity or disclosure risks that a simple market cap calculation cannot diagnose.