A millionaire is commonly defined as a person whose total assets minus liabilities — their net worth — equals at least one million units of a given currency. In ordinary usage the term most often refers to the U.S. dollar, but it may equally apply to euros, pounds, yen or other currencies. Net worth is a snapshot that combines liquid assets (cash and bank balances), financial instruments such as holdings in the stock market, and nonfinancial assets like real estate, minus debts such as mortgages and loans.

Calculation and components

Being a millionaire refers to accumulated wealth rather than to annual income. Common components included when estimating net worth are:

  • Liquid assets: cash, savings and short-term deposits.
  • Investments: publicly traded stocks, bonds, mutual funds and retirement accounts.
  • Real estate: value of primary residence and any investment properties, net of mortgages.
  • Business equity: ownership stakes in private enterprises and partnerships.
  • Collectibles and other tangible valuables, after deducting any secured debts.

Different organizations apply different rules: some wealth reports count only investable assets (excluding primary residence), while broader surveys use total net worth. Currency exchange rates and inflation change the real value of a million units over time, so being a millionaire in one currency does not always carry the same purchasing power internationally.

Variations in terminology

Related terms describe different magnitudes of wealth. Multimillionaire is an informal label for someone with multiple millions of currency units in net worth; its lower bound varies by context. Financial institutions commonly use the term high-net-worth individual (HNWI) to mean a person with at least one million dollars (or equivalent) in investable assets. Banks and wealth managers often use ultra-high-net-worth (UHNW) to refer to individuals with substantially greater sums, typically starting at tens of millions of dollars. At the top end, a billionaire has at least one billion units of currency.

Distribution and notable figures

The number and concentration of millionaires fluctuate with economic growth, asset price changes and exchange rates. Some global wealth reports have estimated that, as of mid‑2020, there were on the order of tens of millions of people classified as U.S.-dollar millionaires worldwide. For example, certain studies estimated about 13 million U.S.-dollar millionaires globally around that time, with a substantial share living in the United States. In some reports the United States (often referred to in shorthand as America) accounted for several million such individuals, and major cities like New York frequently rank among those with the largest absolute numbers of wealthy residents. Financial centers and small jurisdictions are sometimes highlighted for high per-capita concentrations of affluent individuals; for instance, Geneva is often cited for its high density of wealthy residents relative to population.

History and social context

The term "millionaire" became socially salient as industrialization, expanding capital markets and international trade allowed more people to accumulate substantial private wealth. Over time it evolved from a marker of rare wealth to a more common benchmark in many advanced economies, though social perceptions of what constitutes "wealthy" vary by culture, era and local cost of living.

Economic and policy implications

Counts of millionaires are used by analysts, policymakers and commentators when discussing inequality, taxation and wealth mobility. The classification influences market targeting by financial services and can affect debates over progressive taxation, wealth reporting and public policy. Methodological differences — for example whether to include primary residences or how to value private business interests — lead to different estimates across sources, so readers should consult the methodology sections of wealth reports and national statistics when comparing figures (assets and wealth).

Further reading

For technical definitions, up-to-date estimates, and regional breakdowns, consult published wealth surveys, central bank or statistical office data, and reports produced by private wealth research firms. These sources differ in scope and methods, so cross-referencing multiple reports can provide a clearer picture of global and local distributions of millionaires.

Key terms introduced above — net worth, U.S. dollar, stock market, assets and wealth, America, New York, and Geneva — appear as entry points to more detailed discussions in specialized sources.