Market Cap Calculator
Company market value, exact dollars, and size band from price and shares outstanding.
What it does
Market capitalization prices the whole company: one share times every share out there. Index funds, risk models, and headlines all sort stocks by it rather than by price alone.
The tool above takes share price with shares outstanding. It returns the scaled value with exact dollars and the size band beside them.
The default of $250 with 10 billion shares gives $2.5 trillion ($2,500,000,000,000.00 exact): mega cap. A $50 stock with 100 million shares gives $5 billion: mid cap.
The definition follows SEC market education with FINRA stock basics matching each term. Both define capitalization as price times shares and describe large, mid, small, and micro bands the same way.
How to use
- Enter the current share price.
- Enter total shares outstanding, not your holding.
- Read market cap first for the headline value.
- Read exact dollars for the full figure.
- Read the band to place the company.
Formula
- price
- Current per share market price.
- shares
- All company shares outstanding.
- bands
- Conventional size cutoffs, varying slightly by source.
Splits leave cap unchanged since price and shares move oppositely. Enterprise value adds debt and subtracts cash for takeover math, sitting outside this page.
Worked example
Example: $250 with 10 billion shares
Defaults: price 250, shares 10000000000.
- Multiply: 250 x 10,000,000,000 = $2,500,000,000,000.00.
- Scale: 2,500 billions = $2.5 trillion.
- Band: above 200B reads Mega cap.
- Split check: 2-for-1 would give $125 with 20B, same cap.
- Tool shows $2.5 trillion, exact dollars, Mega cap.
Reference table
| Price x shares | Market cap | Band |
|---|---|---|
| $250 x 10B | $2.5 trillion | Mega cap |
| $50 x 100M | $5 billion | Mid cap |
| $10 x 10M | $100 million | Micro cap |
Limits
- Market value only; cash, debt, and value differ.
- Bands are conventions with fuzzy edges.
- After hours prices swing the label.
- Dilution from new issues needs fresh share counts.
Common mistakes
- Calling a high price a big company.
- Using personal holdings instead of outstanding shares.
- Mixing millions with billions in share counts.
- Treating market cap as takeover price.
- Forgetting splits reband nothing by themselves.
Try it yourself
Quick checks. Answers sit tucked under each question.
$50 with 100M shares?
$5,000,000,000.00 ($5 billion): Mid cap.
$10 with 10M shares?
$100,000,000.00 ($100 million): Micro cap.
Effect of a 2-for-1 split?
None on cap: price halves while shares double.
Questions
How do I calculate market cap?
Price times shares outstanding. $250 times 10B is $2.5T.
What is a mega cap?
About $200B and up. Large runs near $10B, mid $2-10B, small below that.
Price or cap for size?
Cap. A $500 stock with few shares can be smaller than a $10 stock with billions out.
Market cap versus value?
Cap prices equity only. Enterprise value adds debt and removes cash.
Do splits change cap?
No. Equal and opposite moves in price and shares cancel out.
Why bands matter?
Funds, indexes, and risk models allocate by band, moving prices with flows.