What are the market cap size thresholds?

Common classifications: mega-cap >$200B, large-cap $10B-$200B, mid-cap $2B-$10B, small-cap $300M-$2B, micro-cap $50M-$300M, nano-cap <$50M. These thresholds shift over time with overall market levels.

How does a stock buyback affect market cap?

A buyback reduces shares outstanding. If the stock price stays the same, market cap falls by the amount spent on buybacks. In practice, buybacks often signal management confidence and can push the price up, partially or fully offsetting the share reduction.

Is market cap the same as a company's net worth?

No. Net worth (book value) is assets minus liabilities on the balance sheet. Market cap reflects what investors are willing to pay for future earnings, which often diverges significantly from book value. Growth companies trade at large premiums to book value; distressed companies may trade below it.

Market Capitalization Calculator

Calculate a company's market capitalization — the total market value of all outstanding shares. Enter the current share price and the number of shares outstanding to determine if a stock is large-cap, mid-cap, or small-cap.

By AbraCalc Editorial Team · Reviewed by AbraCalc Methodology Review · Last reviewed: 2026-06-25

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How to use this tool

Enter current share price and shares outstanding in the fields above.
Results update instantly as you type — or click Calculate.
Read your market capitalization and the full breakdown beneath it.

⚠ This tool provides general estimates for education only and is not financial, tax or legal advice. Figures may not reflect your situation — verify with a qualified professional.

Formula

Market Cap = Share Price × Shares Outstanding

How it works

Market capitalization represents the total dollar value of a company's outstanding equity shares at the current market price. It is the most widely used measure of a company's size and is the basis for stock index construction and asset allocation benchmarks.

Market cap is classified into tiers: mega-cap (>$200B), large-cap ($10B–$200B), mid-cap ($2B–$10B), small-cap ($300M–$2B), and micro-cap (<$300M). These ranges are approximate and evolve over time with market levels.

Worked example

Company with $150 Share Price and 1,000,000 Shares

Market cap = $150 × 1,000,000 = $150,000,000
In millions: $150,000,000 ÷ 1,000,000 = $150.000 million
In billions: $150,000,000 ÷ 1,000,000,000 = $0.150000 billion

Market capitalization is $150,000,000 ($150.000M), placing this company in the small-cap tier.

Common mistakes to avoid

Using authorized shares instead of shares outstanding — authorized shares include unissued shares that have no effect on market cap; only issued and outstanding shares count.
Forgetting to add the value of preferred stock and convertible securities when computing enterprise value, which is a different (and often more relevant) concept than market cap.
Treating market cap as the price to acquire a company — a buyout price includes a control premium, and acquirers must also assume or repay debt, making enterprise value the more relevant takeover metric.

Key terms

What is market capitalization?: Market capitalization is the total market value of a company's outstanding shares, calculated as share price multiplied by shares outstanding. It represents what the market collectively believes the company's equity is worth.
What counts as large-cap vs small-cap?: Definitions vary, but a common convention is: mega-cap >$200B, large-cap $10B–$200B, mid-cap $2B–$10B, small-cap $300M–$2B, micro-cap <$300M, nano-cap <$50M.
Is market cap the same as company value?: Market cap measures only the equity value. Enterprise value (EV) adds debt and subtracts cash to capture the full cost of acquiring a business and is often a more complete measure of company value.
What are shares outstanding?: Shares outstanding are all shares of a corporation currently held by shareholders, including institutional investors and insiders. Treasury shares repurchased by the company are excluded.
Does market cap change every day?: Yes. Because it is tied to the share price, market cap fluctuates continuously during trading hours as the stock price moves, even if the number of shares outstanding stays constant.

Frequently asked questions

What are the market cap size thresholds?: Common classifications: mega-cap >$200B, large-cap $10B-$200B, mid-cap $2B-$10B, small-cap $300M-$2B, micro-cap $50M-$300M, nano-cap <$50M. These thresholds shift over time with overall market levels.
How does a stock buyback affect market cap?: A buyback reduces shares outstanding. If the stock price stays the same, market cap falls by the amount spent on buybacks. In practice, buybacks often signal management confidence and can push the price up, partially or fully offsetting the share reduction.
Is market cap the same as a company's net worth?: No. Net worth (book value) is assets minus liabilities on the balance sheet. Market cap reflects what investors are willing to pay for future earnings, which often diverges significantly from book value. Growth companies trade at large premiums to book value; distressed companies may trade below it.