Base currency definition
The first currency in a currency pair. It shows how much the base currency is worth as measured against the second currency. For example, if the USD/CHF (U.S. Dollar/Swiss Franc) rate equals 1.6215, then one USD is worth CHF 1.6215. In the forex market, the US dollar is normally considered the base currency for quotes, meaning that quotes are expressed as a unit of $1 USD per the other currency quoted in the pair. The primary exceptions to this rule are the British pound, the euro and the Australian dollar.