Last updated: March 2026
Understanding Exchange Rates
An exchange rate tells you how much one currency is worth in terms of another. It is the fundamental mechanism that enables international trade, travel, and investment. Without exchange rates, a Japanese manufacturer could not sell cars in Europe and an American tourist could not buy dinner in Paris.
Exchange rates are quoted as currency pairs. The first currency (the base) is always equal to one unit, and the second currency (the quote) shows how much of it you get. For example, EUR/USD = 1.08 means one Euro buys 1.08 US Dollars. This calculator lets you convert between any two of the 50+ supported currencies using live mid-market rates.
How the Forex Market Sets Exchange Rates
The foreign exchange market is a decentralized global marketplace where currencies are traded. Unlike stock exchanges with physical floors, forex operates as an electronic network of banks, institutions, and individual traders connected 24 hours a day, five days a week. Trading begins in Sydney, moves to Tokyo, then London, and finally New York before cycling back.
At approximately $7.5 trillion in daily volume, the forex market dwarfs every other financial market on Earth. London is the largest center, handling about 38% of global forex turnover, followed by New York (19%), Singapore (9%), and Hong Kong (7%). The sheer volume means that exchange rates are among the most efficiently priced assets in the world.
Fixed vs. Floating Exchange Rate Systems
Most major currencies today use floating exchange rates, where the value is determined purely by market supply and demand. The US Dollar, Euro, British Pound, Japanese Yen, and most developed-market currencies float freely. Their rates change continuously throughout the trading day.
Some countries choose to peg (fix) their currency to another currency, usually the US Dollar. The Hong Kong Dollar, Saudi Riyal, and UAE Dirham are notable examples of pegged currencies. China uses a managed float, where the People's Bank of China sets a daily reference rate and allows the Yuan to trade within a narrow band around it. Pegged systems provide stability but require large foreign exchange reserves to defend the peg.
Bid, Ask, Spread, and the Mid-Market Rate
When you exchange currency, you encounter three key numbers: the bid price (what a dealer pays to buy), the ask price (what they charge to sell), and the spread (the difference between the two). The mid-market rate sits exactly between the bid and ask and represents the truest value of the exchange rate.
This calculator displays mid-market rates, which are the standard benchmark used by financial professionals. When comparing exchange services, subtract the mid-market rate from the rate you are offered to see exactly how much you are being charged in hidden markup. Competitive online services charge less than 1% over mid-market, while traditional banks may charge 2-5% and airport kiosks 8-12%.
Frequently Asked Questions
What is an exchange rate?
An exchange rate is the price of one currency expressed in terms of another. For example, if the USD/EUR exchange rate is 0.92, it means one US Dollar can be exchanged for 0.92 Euros. Exchange rates are determined by the foreign exchange (forex) market, where currencies are bought and sold 24 hours a day, five days a week. Rates constantly fluctuate based on supply and demand.
What is the difference between fixed and floating exchange rates?
In a floating exchange rate system, the currency's value is determined by market forces — supply and demand on the forex market. Most major currencies (USD, EUR, GBP, JPY) use floating rates. In a fixed (pegged) exchange rate system, a government or central bank ties its currency's value to another currency or basket of currencies. For example, the Hong Kong Dollar is pegged to the US Dollar at approximately 7.8 HKD per USD.
What are bid, ask, and mid-market rates?
The bid rate is the price at which a dealer will buy a currency, and the ask rate is the price at which they will sell it. The difference between the two is called the spread, which represents the dealer's profit. The mid-market rate is the midpoint between bid and ask and represents the fairest exchange rate. This calculator shows mid-market rates, which are the standard benchmark for comparing exchange services.
How do central banks influence exchange rates?
Central banks influence exchange rates primarily through monetary policy — adjusting interest rates and controlling the money supply. Higher interest rates attract foreign capital, increasing demand for the currency and pushing its value up. Central banks can also intervene directly by buying or selling their own currency on the open market, though this is typically reserved for extreme situations. Verbal guidance (forward guidance) also moves markets.
What is purchasing power parity (PPP)?
Purchasing power parity is an economic theory suggesting that exchange rates should adjust so that identical goods cost the same in different countries when converted to a common currency. The famous 'Big Mac Index' by The Economist is a lighthearted version of this concept. In practice, exchange rates often deviate significantly from PPP due to trade barriers, transportation costs, non-tradeable services, and capital flows.
How can I protect myself from exchange rate risk?
Businesses and investors use several strategies to manage exchange rate risk (also called currency risk). Forward contracts lock in a rate for a future date. Currency options give the right but not the obligation to exchange at a set rate. Natural hedging involves matching revenues and expenses in the same currency. For travelers, using credit cards with no foreign transaction fees and avoiding dynamic currency conversion are the simplest protections.