Base currency
The base currency is the first currency in a pair. The quoted exchange rate is normally interpreted for one unit of this currency.
Learn how two currencies form one Forex quote, how the base and quote currencies divide the pair, and why pair direction controls how a quoted rate must be read.
Educational information only. Example rates are illustrative manual inputs, not live prices, executable quotes, investment advice or a recommendation to trade.
Currency pair structure is the ordering system that combines two currency codes into one exchange-rate instrument. The first code identifies the currency being priced. The second identifies the currency used to express that price.
Forex does not normally present a currency as a standalone tradable price. A currency is valued relative to another currency. The symbol EUR/USD, for example, combines the euro and the US dollar into one pair.
The displayed rate answers a specific question: how many US dollars are used to represent one euro?
This relationship is the prerequisite for understanding how an exchange rate should be read , which side of a quote is the bid or ask, how a spread is calculated, where a pip sits and how a cross rate is derived.
An exchange rate is a relative price. It cannot describe the value of one currency without identifying the currency against which that value is measured.
The quoted price represents the number of quote-currency units associated with one unit of the base currency.
If EUR/USD is 1.1000, the rate does not mean 1.1000 euros. It means that one euro is represented by 1.1000 US dollars.
The two codes can be analysed separately, but the quoted instrument is their relationship. EUR is the base component, USD is the quote component and EUR/USD is the complete pricing expression.
The order of the codes assigns a distinct job to each currency. Neither position is decorative. The first code establishes the unit to which the quoted rate applies, while the second establishes the denomination of that rate.
The base currency is the first currency in a pair. The quoted exchange rate is normally interpreted for one unit of this currency.
The quote currency is the second currency in a pair. It provides the units in which the base currency’s price is expressed.
The rate joins the two positions mathematically. Where the pair price is expressed as quote currency per unit of base currency, the basic relationship is:
Base-currency amount multiplied by the pair rate produces the corresponding quote-currency amount.
Pair direction determines which currency is treated as the one-unit base and which currency supplies the pricing units. EUR/USD and USD/EUR contain the same currencies, but they are not interchangeable labels for the same displayed rate.
EUR/USD places EUR first. The euro is therefore the base currency and the US dollar is the quote currency.
EUR/USD 1.1000 means one euro is priced at 1.1000 US dollars.
USD/JPY places the US dollar first and the Japanese yen second.
USD/JPY 154.00 means one US dollar is priced at 154 Japanese yen.
Reversing the symbols changes the denominator of the pricing relationship.
The inverse expresses euros per US dollar instead of US dollars per euro. It preserves the mathematical relationship while changing the unit interpretation.
Direct, indirect and inverse quotation are covered more fully in the Exchange Rate Hub .
Currency pairs are normally assembled from recognised alphabetic currency identifiers. ISO 4217 provides three-letter alphabetic representations for currencies and certain monetary units.
Full currency names are too long for compact financial systems and may differ across languages. Standardised codes reduce ambiguity in market data, settlement instructions, accounting records and software interfaces.
| Code | Currency | Example position |
|---|---|---|
| EUR | Euro | Base in EUR/USD |
| USD | US Dollar | Quote in EUR/USD; base in USD/JPY |
| JPY | Japanese Yen | Quote in USD/JPY |
| GBP | Pound Sterling | Base in GBP/USD |
| CHF | Swiss Franc | Quote in USD/CHF |
The slash is a readability separator, not part of either currency code. Software systems may remove it or use another delimiter while preserving the same six-letter sequence.
EUR/USDSlash notationEURUSDCompact notationEUR-USDHyphenated notationEUR USDSpace-separated notation
A platform or broker may extend a symbol for internal classification.
An example is EURUSD.m. The extension may identify an
account category, contract group or another platform-specific configuration.
XAU and XAG are internationally used codes for gold and silver rather than national currencies. Platforms may display XAU/USD or XAG/USD using pair-like notation. The parser labels these as precious-metal codes.
Pair classification does not replace the base-and-quote rule. Whether a pair is described as major, minor, cross or exotic, the first code still acts as the base and the second acts as the quote.
EUR is the base and USD is the quote.
EUR is the base and GBP is the quote.
USD is the base and ZAR is the quote.
Category labels describe market composition or common usage. Pair structure describes notation and pricing direction.
For full classifications and examples, continue to the Currency Pair Types guide .
The US dollar remains central to global FX pair composition. The dollar appeared on one side of 89.2% of reported FX trades measured in the BIS April 2025 survey. This describes market usage; it does not mean every currency pair must contain USD.
The same method applies across pair formats: identify the first code, identify the second code and express the rate as quote-currency units per one base-currency unit.
| Pair | Base | Quote | Plain-English direction |
|---|---|---|---|
| EUR/USD | EUR | USD | US dollars per euro |
| GBP/USD | GBP | USD | US dollars per pound sterling |
| USD/JPY | USD | JPY | Japanese yen per US dollar |
| USD/CHF | USD | CHF | Swiss francs per US dollar |
| AUD/NZD | AUD | NZD | New Zealand dollars per Australian dollar |
| EUR/GBP | EUR | GBP | Pounds sterling per euro |
Start with “one unit of the first currency” and complete the sentence using the second currency.
EUR/USD expresses USD per EUR. Reading it as euros per US dollar reverses the pricing direction.
The first position defines the base unit. Payment and settlement depend on the transaction and should not be inferred from pair position alone.
Being listed first does not prove that a currency is stronger, safer, more stable or more valuable.
A slash may be removed and broker-specific extensions may be added. The underlying codes should be normalised first.
Base and quote identify the currencies. Bid and ask identify two price sides for the same pair. Continue to the Bid & Ask Pricing Hub .
In EURUSD.m, the core pair is EUR/USD. The extension is not part of either three-letter currency code.
Use this hub as the overview, then move into the page that owns the precise question you are trying to answer.
Parse pair symbols, identify base and quote currencies and normalise common notation.
Open the tool → 01Examine why two currencies combine into one tradable pricing relationship.
Read the guide → 02Understand the first currency, the one-unit convention and its pricing role.
Read the guide → 03Learn how the second currency provides the units used to express price.
Read the guide → Next hubMove from pair anatomy to direct, inverse and plain-English rate interpretation.
Continue learning →The article uses institutional and official material for currency codes, quotation mechanics and market context. Broker-specific extensions should be checked against the relevant platform’s own symbol specification.
| # | Verified point | Primary source | Used in |
|---|---|---|---|
| 1 | ISO 4217 provides recognised alphabetic and numeric currency representations. | ISO Currency Codes | Codes and notation |
| 2 | Exchange rates are represented by currency pairs with the base currency listed first. | BIS Foreign Exchange Market Paper | Pair structure and direction |
| 3 | Quote notional can be derived from base notional multiplied by the relevant spot rate. | CME FX Quotation and Pricing Guide | Base-to-quote calculation |
| 4 | The US dollar appeared on one side of 89.2% of reported FX trades measured in April 2025. | BIS 2025 Triennial FX Survey | Market context |
Currency pair structure begins with a fixed reading order. The first currency is the base, the second is the quote and the displayed price states how many quote-currency units represent one base-currency unit.
The rule remains consistent whether the pair contains the US dollar, forms a non-dollar cross or includes a less frequently traded currency.
Formatting may change across platforms, but the underlying currency sequence must be identified before the price can be interpreted correctly.
Practise the structure with the Currency Pair Parser , then continue to the Exchange Rate Hub to understand what the quoted number means and how inversion changes its presentation.
The first currency is the base currency. The quoted exchange rate is normally interpreted for one unit of that currency.
The second currency is the quote currency. It provides the units in which the base currency’s price is expressed.
It means one euro, the base currency, is priced at 1.1000 US dollars, the quote currency.
Yes. Reversing the pair changes the base currency, quote currency and unit interpretation. The corresponding mathematical rate is normally obtained through inversion.
The slash is a visual separator. EURUSD and EUR/USD can represent the same underlying currency sequence.
No. First position identifies the base currency under the quotation convention. It does not prove that the currency is stronger or more valuable.
XAU and XAG are precious-metal codes for gold and silver. Platforms frequently combine them with currency codes in pair-like symbols such as XAU/USD.