How Currency Exchange Rates Actually Work
An exchange rate is the price of one currency in terms of another, set by global currency markets and updated continuously as currencies are bought and sold. The rate you see on a converter is typically the mid-market reference rate — banks and card providers almost always add their own margin on top, which is why the rate you're actually charged is usually less favorable.
The number a currency converter shows and the number that actually appears on a bank statement are rarely identical, and the gap between them isn't a bug — it's a business model. Understanding the difference is the easiest way to avoid overpaying on a currency exchange.
What the "reference rate" actually is
The mid-market rate — sometimes called the interbank or reference rate — is the midpoint between what large financial institutions are buying and selling a currency for at a given moment. It's the rate you'll see quoted in the news, on Google, and on most currency converters, and it moves continuously throughout the trading day.
No individual consumer actually transacts at the exact mid-market rate, because banks, card networks, and currency exchange kiosks each add their own margin on top to cover their costs and generate profit.
Why your card or bank charges a different number
Credit and debit cards typically apply the network's rate (close to mid-market) but often add a separate foreign transaction fee — commonly 1–3% of the purchase. Banks doing a wire transfer or currency exchange often bake their margin directly into the rate itself rather than charging a visible fee, which makes it harder to spot without comparing against the reference rate first.
Airport kiosks and hotel currency exchanges tend to have the widest margins of all, since they're pricing for convenience rather than competing on rate — worth avoiding for anything beyond a small emergency amount.
How to get closer to the real rate
Check the mid-market reference rate before any exchange so you have a baseline to compare against. A no-foreign-transaction-fee card generally gets you closest to that reference rate for purchases; for cash, a card-linked ATM withdrawal in the local currency is usually cheaper than exchanging cash at a kiosk, though it's worth checking your bank's ATM fee first.