How Exchange Rates Work

Anyone who has changed money for a holiday has met an exchange rate, even if they did not stop to think about it. The number on the bureau's board decides how far your money goes abroad. The same number, scaled up, shapes the price of imports, the fortunes of exporters and the inflation rate of entire countries. Here is how it works.

What an exchange rate is

An exchange rate is the price of one currency expressed in terms of another. If one unit of currency A buys 1.2 units of currency B, that ratio is the exchange rate between them. Like any price, it can rise or fall.

When a currency can buy more of another than it could before, it has appreciated or grown stronger. When it buys less, it has depreciated or weakened. These movements are constant for most major currencies, ticking up and down throughout every trading day.

Floating versus fixed regimes

Countries choose how their currency's value is set, and the choices fall into two broad camps.

• Floating rates are determined by supply and demand in global currency markets. If more people want to buy a currency than sell it, its price rises; if more want to sell, it falls. Most large economies let their currencies float, intervening only occasionally.
• Fixed or pegged rates are held at a chosen level against a reference currency or basket. To keep the peg, the authorities stand ready to buy or sell their own currency, and they may shape interest rates around defending it.

Each approach has trade-offs. Floating rates absorb shocks automatically and free policymakers to focus on the domestic economy, but they can be volatile. Fixed rates offer stability and predictability for trade, but defending a peg can be costly and can break under pressure if markets doubt it.

A peg is a promise. It works only as long as markets believe the authorities have the will and the reserves to keep it.

Some countries adopt a managed middle path, letting the currency move within limits or steering it gently rather than fixing it rigidly.

What moves a currency

For a floating currency, the value reflects the balance of everyone wanting to buy and sell it. Several forces drive that balance.

1. Trade flows. When a country exports goods and services, foreign buyers need its currency to pay, which raises demand. Heavy importing works the other way, as buyers sell the home currency to obtain foreign ones.
2. Interest rates. Higher returns can attract foreign savers and investors seeking yield, lifting demand for the currency. Lower rates can reduce that pull.
3. Inflation. A currency that loses purchasing power quickly at home tends to weaken against currencies that hold their value, because its real return is eroded.
4. Confidence and stability. Political stability, sound institutions and a credible economic outlook make a currency attractive to hold. Uncertainty or crisis can trigger selling.

These forces interact and sometimes pull in opposite directions, which is why predicting currency moves is notoriously difficult even for experts.

Why it matters for travel

The most visible effect is on travel. A strong home currency means your money stretches further abroad: hotels, meals and souvenirs feel cheaper. A weak home currency makes the same trip more expensive, while making your own country a bargain for incoming visitors. Tourism flows often shift with exchange rates for exactly this reason.

Why it matters for trade

For businesses that buy and sell across borders, exchange rates are a daily concern.

• A weaker currency makes a country's exports cheaper and more competitive abroad, which can boost manufacturers and farmers selling overseas.
• A stronger currency makes imports cheaper, helping companies that rely on foreign parts and consumers who buy imported goods.

Because rates move, firms that trade internationally often try to manage the risk that a sudden swing wipes out their profit margin on a deal.

Why it matters for inflation

Exchange rates feed directly into the cost of living. When a currency weakens, everything a country imports becomes more expensive in local terms, from fuel and food to electronics and raw materials. Those higher costs can ripple through the economy and push up the general price level. A stronger currency does the reverse, making imports cheaper and easing price pressure. This is one reason central banks watch their currency closely even when they do not target it directly.

The bottom line

An exchange rate is just a price, but it is one of the most consequential prices in any economy. Whether a currency floats freely or is held to a peg, its level is shaped by trade, interest rates, inflation and confidence, and in turn it shapes the cost of a holiday, the competitiveness of exporters and the inflation households feel. Understanding it turns a baffling board of numbers into a readable signal about how a country sits in the wider world.