What this calculator does
Market capitalisation, usually shortened to market cap, is the total value the stock market places on a company's equity. It is calculated by multiplying the current share price by the total number of shares outstanding, giving a single figure for what buying every share in the company would cost at that price.
Market cap is a market-set number, not a measure of the company's assets, revenue or profit. Two companies can have very different market caps despite similar earnings, because the market is pricing in different growth expectations, risk or sentiment. It is also the figure used to sort companies into size categories, such as large-cap, mid-cap and small-cap.
The formula
Multiply the current share price by the total number of shares outstanding. Both figures are usually published alongside a stock quote, and the share count changes over time as companies issue new shares or buy back existing ones.
| Term | Meaning |
|---|---|
| Market cap | Total market value of a company's equity: share price × shares outstanding. |
| Shares outstanding | The total number of shares currently held by all shareholders, including insiders and institutions. |
| Share price | The current price of one share on the exchange it trades on. |
The inputs explained
| Field | What to enter |
|---|---|
| Share price ($) | The current share price, in whatever currency the stock trades in. |
| Shares outstanding | The total number of shares outstanding, as reported by the company or the exchange. |
When to use it
Sizing up a company at a glance
Market cap converts a raw share price, which says nothing about company size on its own, into a comparable figure for how large the market considers the whole business.
Comparing companies with very different share prices
A $500 share price does not mean a company is worth more than one trading at $20; market cap corrects for the number of shares each has outstanding and puts them on the same footing.
Tracking how a price move affects total value
Applying a percentage price change to the current share count shows how much total market value that move actually represents, which is often a far larger or smaller number than the percentage alone suggests.
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
How market cap changes with share price
A fixed 100 million shares outstanding, across a range of share prices.
| Share price | Market capitalisation |
|---|---|
| $10 | $1,000,000,000.00 |
| $20 | $2,000,000,000.00 |
| $50 | $5,000,000,000.00 |
| $100 | $10,000,000,000.00 |
| $200 | $20,000,000,000.00 |
| $500 | $50,000,000,000.00 |
How market cap changes with shares outstanding
A fixed $50 share price, across a range of share counts.
| Shares outstanding | Market capitalisation |
|---|---|
| 1,000,000 | $50,000,000.00 |
| 5,000,000 | $250,000,000.00 |
| 10,000,000 | $500,000,000.00 |
| 50,000,000 | $2,500,000,000.00 |
| 100,000,000 | $5,000,000,000.00 |
| 500,000,000 | $25,000,000,000.00 |
Questions
Is market cap the same as how much a company is worth?
It is the market's valuation of the company's equity at the current share price, not an independent measure of intrinsic value. It also excludes debt, which is why enterprise value (market cap plus debt, minus cash) is used for some comparisons instead.
What counts as large-cap, mid-cap and small-cap?
The exact thresholds vary by index and market, but large-cap generally refers to the biggest, most established companies, mid-cap to mid-sized growing companies, and small-cap to smaller, often higher-risk companies. The categories are relative and shift over time as markets grow.
Why does market cap change even when the company has not done anything?
Market cap moves with the share price, which is set by trading throughout the day based on supply, demand and sentiment, not only on company news. A market cap can rise or fall with the whole market even when nothing has changed at the company itself.
Does buying back shares change market cap?
A buyback reduces the number of shares outstanding. If the share price stayed exactly the same, market cap would fall in proportion, but buybacks often support the share price too, so the actual effect on market cap depends on how the market reacts.
For a company's value per individual share rather than in total, see the earnings per share calculator. To see how the share price relates to earnings, use the P/E ratio calculator.