A fixed exchange rate, sometimes called a pegged exchange rate, is also referred to as the Tag of particular Rate, which is a type of exchange rate regime wherein currency's value is matched to the value of another single currency or to a basket of other currencies, or to another measure of value, such as gold.

A fixed exchange rate is usually used to stabilize the value of a currency against the currency it is pegged to. This makes trade and investments between the two countries easier and more predictable and is especially useful for small economies in which external trade forms a large part of their GDP.

It can also be used as a means to control inflation. However, as the reference value rises and falls, so does the currency pegged to it. In addition, according to the Mundell–Fleming model, with perfect capital mobility, a fixed exchange rate prevents a government from using domestic monetary policy in order to achieve macroeconomic stability.

There are no major economic players that use a fixed exchange rate (except the countries using the euro and the Chinese yuan). The currencies of the countries that now use the euro are still existing (for old bonds). The rates of these currencies are fixed with respect to the euro and to each other. The most recent such country to discontinue their fixed exchange rate was the People's Republic of China, which did so in July 2005. However, as of September 2010, the fixed-exchange rate of the Chinese yuan has already increased 1.5% in the last 3 months.

In finance, an exchange rate (also known as the foreign-exchange rate, forex rate or FX rate) between two currencies is the rate at which one currency will be exchanged for another. It is also regarded as the value of one country’s currency in terms of another currency. For example, an interbank exchange rate of 91 Japanese yen (JPY, ¥) to the United States dollar (US$) means that ¥91 will be exchanged for each US$1 or that US$1 will be exchanged for each ¥91. Exchange rates are determined in the foreign exchange market, which is open to a wide range of different types of buyers and sellers where currency trading is continuous: 24 hours a day except weekends, i.e. trading from 20:15 GMT on Sunday until 22:00 GMT Friday. The spot exchange rate refers to the current exchange rate. The forward exchange rate refers to an exchange rate that is quoted and traded today but for delivery and payment on a specific future date.

In the retail currency exchange market, a different buying rate and selling rate will be quoted by money dealers. Most trades are to or from the local currency. The buying rate is the rate at which money dealers will buy foreign currency, and the selling rate is the rate at which they will sell the currency. The quoted rates will incorporate an allowance for a dealer's margin (or profit) in trading, or else the margin may be recovered in the form of a "commission" or in some other way. Different rates may also be quoted for cash (usually notes only), a documentary form (such as traveller's cheques) or electronically (such as a credit card purchase). The higher rate on documentary transactions is due to the additional time and cost of clearing the document, while the cash is available for resale immediately. Some dealers on the other hand prefer documentary transactions because of the security concerns with cash.