Market Capitalization Calculator

Calculate market cap, enterprise value, P/E, and P/S ratios. Classify stocks by cap tier and compare valuation metrics against major index benchmarks.

About the Market Capitalization Calculator

Market capitalization — share price multiplied by shares outstanding — is the most fundamental measure of a company's size and total market value. It determines index inclusion, institutional investment eligibility, and risk classification.

Market cap alone doesn't tell the full story. Enterprise value (EV) adds debt and subtracts cash to show what it would cost to acquire the entire business. Valuation multiples like P/E (price-to-earnings) and P/S (price-to-sales) put the market cap in context relative to the company's financial performance.

This calculator computes market cap, enterprise value, key valuation ratios, and classifies the stock into standard cap tiers: Mega Cap ($200B+), Large Cap ($10B+), Mid Cap ($2B+), Small Cap ($300M+), Micro Cap ($50M+), and Nano Cap. The scenario table shows how share price changes affect market cap and tier classification, while benchmark comparisons position your stock relative to major index averages.

Use the preset examples to load common values instantly, or type in custom inputs to see results in real time. The output updates as you type, making it practical to compare different scenarios without resetting the page.

Why Use This Market Capitalization Calculator?

Market cap is the starting point for classifying a stock, but investors usually need more than that headline number. This calculator ties market cap to enterprise value and valuation multiples so you can see size, capital structure, and pricing in one view.

How to Use This Calculator

  1. Enter the current share price and total shares outstanding.
  2. Add EPS and annual revenue for valuation multiples.
  3. Enter debt, cash, and preferred stock for enterprise value.
  4. Review market cap, cap tier, and valuation ratios.
  5. Check the price scenario table to see tier transition points.
  6. Compare your valuation ratios against major index averages.

Formula

Market Cap = Share Price × Shares Outstanding Enterprise Value = Market Cap + Total Debt − Cash + Preferred Stock P/E = Share Price / EPS P/S = Market Cap / Annual Revenue EV/Revenue = Enterprise Value / Revenue

Example Calculation

Result: Market Cap = $22.5B (Large Cap), P/E = 21.4×

$45 × 500M shares = $22.5B market cap, placing it in the Large Cap tier. At $2.10 EPS, the P/E ratio is 21.4× — roughly in line with the S&P 500 average.

Tips & Best Practices

Size Is Only The First Layer

Market cap tells you what the equity market says the company is worth today, but it does not show how much debt sits behind that equity. Enterprise value is often the better comparison tool when two companies have very different balance sheets.

Watch Tier Boundaries

A stock near the line between small cap, mid cap, and large cap can move between classification buckets quickly. That matters for index inclusion, fund mandates, and how investors frame the company’s risk profile.

Use Fresh Share Counts

The market-cap math is simple, but the share count is not always static. Buybacks, stock-based compensation, convertible securities, and new issuance can all change the result materially.

Sources & Methodology

Last updated:

Methodology

This calculator multiplies current share price by shares outstanding to estimate market capitalization, then derives enterprise value and common valuation ratios from the same inputs. The cap tiers are worksheet labels built from widely used Investor.gov size bands, not a regulatory classification.

The scenario table is a sensitivity worksheet that shows how the tier changes if share price moves while share count stays fixed.

Sources

Frequently Asked Questions

What determines market cap classification?

Standard tiers are usually grouped as Mega Cap above $200B, Large Cap above $10B, Mid Cap above $2B, Small Cap above $300M, Micro Cap above $50M, and Nano Cap below that. Different index providers can still use slightly different cutoffs.

Why is enterprise value different from market cap?

EV includes debt (which an acquirer would assume) and subtracts cash (which they'd receive). It represents the total acquisition cost of the business.

Which is better for comparison: P/E or P/S?

P/E is better for profitable companies. P/S is useful for unprofitable or early-stage companies where earnings are negative but revenue exists.

What is a good P/E ratio?

It depends on the sector and growth rate. S&P 500 average is ~22×. Below 15× may indicate value; above 30× suggests growth expectations.

Does market cap include all shares?

Standard market cap uses shares outstanding (which includes restricted shares). Free-float market cap excludes closely held shares and is used for index weighting.

Can market cap change without trading?

Yes. Market cap can change when the share count changes through buybacks, new issuance, option exercise, or stock splits, even if the last traded share price is unchanged.

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