An exchange rate for any pair of currencies other than the official currency of the country where the quoted rate is published. In other words, it is the rate at which two currencies are exchanged based on exchange rates using a third currency. For example, a cross rate may be any rate for a currency exchange in which neither of the currencies involved is that of the country in question (euro/ yen cross for US dollar). In this case, the cross rate of euros for yen could be based on the rate of euros for dollars and dollars for yen, and so on.

A cross rate could also be any currency pair in a transaction where a denominating currency is different from the official currency of a party to the transaction.