How to Calculate Market Capitalisation Across Share Classes

What market cap measures

Market capitalisation, also spelled market capitalization, estimates the equity market value represented by a share price and an outstanding count. One class needs one pair of inputs. An issuer with several classes may need a separate product for each.

Find the right price and outstanding count

Each row represents a distinct share class of one issuer. P is its price per share and Q is the number of actual outstanding shares on the same share basis and valuation date. Enter raw whole shares, including zeros only when explicitly intended.

Outstanding shares are the shares that remain outstanding at the relevant point in time. A reported weighted average for earnings per share answers a different question.

Reconcile one class or an included total

Use one row for a single class, or multiple distinct rows to reconcile a broader estimate. If any relevant class cannot be priced, the included subtotal still describes what you entered. It does not fill the gap.

Multiply each class before adding

Multiply each class price by its own outstanding share count, then sum the unrounded class values. The calculation uses exact scaled prices and whole counts. Confirm all relevant classes before using the company-wide estimate label. The confirmation changes the label and leaves the arithmetic unchanged.

Included market cap = Σ (P × Q)

Verified two-class worked example

Class A has 100 million shares at 12, worth 1.2 billion. Class B has 25 million shares at 8, worth 200 million. The included total is 1.4 billion. Using 12 for both classes would instead give 1.5 billion and would misstate the supplied scenario.

1. Multiply 12 by 100000000 for 1.2 billion.
2. Multiply 8 by 25000000 for 200 million.
3. Add the two values for 1.4 billion.
4. Confirm coverage only if those two classes represent all relevant equity in the model.

Enter prices and counts consistently

Choose the display currency matching the prices you intend to enter. Name each class and enter its price and actual outstanding count. Exclude duplicate listings and depositary receipts for already-counted shares. Confirm completeness only when all relevant classes are represented. Changes clear that confirmation.

If a source reports 25 million shares, enter 25000000. A price in GBX and a price in GBP must be reconciled to pounds before comparing rows.

Read the scope label and totals

Market cap estimates equity market value at supplied prices. An incomplete class list gives an included-class subtotal. Even a confirmed company-wide estimate depends on the coverage, prices and counts you supplied. Market capitalisation is different from enterprise value, fair value, float-adjusted value and your personal holding value.

A class with an unknown quote should stay outside the estimate. Setting that quote to zero would make an explicit zero-value assumption.

Full equity cap, free float and enterprise value

A full equity cap uses the outstanding count. An index may use a float adjustment to reflect shares considered available for trading. S&P DJI and NSE describe such methodology differences.

Enterprise value uses additional financing and cash information. A company with the same equity cap can have very different debt or cash. This calculator does not infer either or assign a fair value.

Keep listings and corporate-action bases aligned

Use one issuer, one major currency and a common valuation date. Quotes and counts must use the same corporate-action basis. A label catches repeats after case and space normalization, but different labels can still refer to the same economic shares.

A depositary receipt may represent a fraction or multiple of a share and can represent equity already counted. The tool cannot infer that relationship from a ticker or label.

Numerical boundaries and display rounding

Enter 1 to 8 classes with distinct labels. Use whole counts through 1e15 and ungrouped prices through 1e9 with up to 12 fractional places. Numeric inputs allow at most 48 trimmed characters. The exact subtotal is bounded by 8 × 10^24. Currency displays cents with tiny-value markers. Rounded row amounts may not add to the rounded total.

An explicit zero price or count makes that row zero. Missing values are invalid. Rounding happens after multiplication and addition, so tiny rows remain in the exact sum.

Common share-count and quote errors

Do not substitute authorised shares, treasury holdings, free float, diluted share counts or EPS-weighted shares. Do not mix dollars with cents or pounds with pence. Expand figures stated in millions, lakhs or crores to actual shares. Do not use a price from before a split with a count from after it.

See the Stock Split and Bonus Share guides for theoretical share-basis adjustments. They help explain why a consistent price and count matter even if both fields are individually valid.

Compare market conventions across five markets

The USA, UK, Canada, Australia and India choices display USD, GBP, CAD, AUD and INR. UK source fields may use pounds millions and India source fields may use lakhs or crores. Enter actual shares and one major currency consistently.

ASX publishes an exchange-specific method. The historical TSX example and S&P DJI methodology illustrate class and float conventions. Compare scope and valuation date before attempting to match a published figure.

Educational scope

Educational estimate for user-supplied equity classes. Excludes live data, missing-class price proxies, FX, listing reconciliation, float adjustments, corporate-action inference, enterprise value and fair value. No personalized investment advice.

Use source disclosures to confirm class counts and valuation timing. The tool does not validate your coverage or price source.

Frequently asked questions

Sources and review

Sources reviewed Nov 7, 2026. Consult current local rules before relying on time-sensitive information.

• Investor.gov: market capitalization
• LSE issuer profile help
• TSX historical index methodology
• ASX market capitalisation methodology
• NSE investible weight factors
• S&P DJI index weighting methodology