You check a currency converter, see a clean number, then your bank or card charges you something noticeably worse. Nobody's lying — you're just looking at two different rates. Understanding the gap helps you spot when a conversion is a fair deal and when it isn't.
The mid-market rate vs the rate you get
The rate you see quoted online is usually the mid-market (or 'interbank') rate — the midpoint between what buyers and sellers are willing to trade a currency for. It's the honest reference number. But banks, cards and exchange desks add a margin (a 'spread') on top, and sometimes a fixed fee, because that's how they make money on the conversion. The rate you actually receive is the mid-market rate minus that margin.
Where our converter's rates come from
We want to be transparent about this: the Currency Converter fetches its rates from Frankfurter, a free public API built on European Central Bank reference rates. Those are mid-market rates. Your currency selection is sent to look up the rate; the amount you type is calculated in your browser and isn't sent anywhere. So the converter shows you the honest reference figure — the baseline to judge any real offer against.
How to compare fairly
- Use the mid-market rate as your benchmark, then ask what margin a provider adds to it.
- Watch for 'zero fee' offers that hide their charge inside a worse rate.
- For a large transfer, a small percentage difference is real money — check it with the Percentage Calculator.
- Rates move during the day, so refresh before a time-sensitive decision.
The takeaway: an online converter tells you what a currency is really worth, not what you'll be charged. Treat the mid-market number as the truth, and measure every provider's offer against it.