Currency Calculator

How the Currency Calculator Works — and What Exchange Rates Really Tell You

Currency conversion looks simple — multiply your amount by an exchange rate and you're done. But the number you see on Google or in our calculator isn't the number you'll actually get at a bank, an airport kiosk, or when you use your credit card abroad. Understanding why — and knowing which rate applies to your situation — can save you real money. This calculator uses live mid-market rates pulled from public financial data, which is the fairest benchmark available to consumers, and the one most financial sites quote.

What a mid-market rate is

The mid-market rate (also called the interbank rate or spot rate) is the midpoint between the buy and sell prices that banks use when trading currencies with each other. It's the most accurate reflection of what one currency is worth in terms of another at any given moment, and it's the rate you'll see quoted on Google, XE, and most financial news sites. Our calculator uses this rate. Crucially, though, no consumer ever gets the mid-market rate — banks and exchange services add a margin on top, which is how they make money. That margin is called the spread, and it varies enormously depending on where you exchange.

Why your actual rate will be worse

Suppose the mid-market rate is 1 USD = 0.92 EUR, and you want to convert $1,000. At the mid-market rate, you'd get €920. But if you exchange at an airport kiosk, they might offer 0.85 — giving you only €850, which is a loss of about 7.6%. That difference is the spread plus fees. Banks typically charge 1–3% over the mid-market rate. Airport kiosks can charge 8–15%. Credit cards usually charge 1–3% plus a foreign transaction fee if your card isn't specifically designed for travel. The best rates are usually found through specialist services like Wise or Revolut, which operate close to the mid-market rate and charge a small, transparent fee instead of hiding profit in the spread.

What moves exchange rates

Exchange rates change constantly, sometimes by the second. The biggest driver is interest rates set by central banks. When a country raises interest rates, its currency tends to strengthen, because foreign investors want to park their money where it earns more. Inflation is another major factor — countries with persistently high inflation see their currency weaken over time. Economic growth, measured by things like GDP and employment, attracts investment and strengthens a currency. And geopolitical events — elections, wars, trade disputes, and natural disasters — can cause sudden, dramatic moves. For most people, though, these factors matter less than the day-to-day reality: if you're converting money, focus on minimizing fees rather than trying to time the market.

Limitations to keep in mind

This calculator uses live rates that refresh periodically, so the result reflects a recent market price — not a guaranteed rate. Real transactions always involve fees, and the final amount you receive will depend on the institution you use. Rates also vary across providers even at the same instant, so it's worth comparing before making a large conversion. If you're converting a substantial amount, even a 0.5% difference in rate can mean hundreds of dollars. The calculator also can't account for weekend and holiday markets, when liquidity is lower and spreads can be wider. And for historical conversions — like figuring out what a 1990 salary would be worth today — you need historical rate data, not live rates. Use this calculator as a benchmark for what a fair conversion looks like, then shop around before committing.