~/tools/exchange-rate-spread
ToolsExchange rate spread calculator
"Zero commission" exchange desks earn their living inside the rate. Compare the rate you are offered with the mid-market rate you see on a price site, and the difference becomes what it really is: a fee with no name on the receipt.
Hidden cost
50
A margin of 4.55% inside the rate.
You would get at mid-market
1,100
You actually get
1,050
Enter both rates in the same direction — how much of the target currency one unit of yours buys. A small per-transaction fee on top is not included here.
How this calculator works
Currency desks rarely charge you where you can see it. The real price hides in the spread: the gap between the mid-market rate — what the currency actually trades at between banks — and the rate you're offered. This calculator divides that gap by the mid-market rate to give the margin as a percentage, then applies it to your amount so the 'free' exchange has a price tag.
A worked example
Google says 1 USD = 30.00 in your currency; the desk offers 29.10. The spread is 0.90, which is 3% of mid-market. Changing $500, that 'commission-free' exchange quietly costs $15. A competitor offering 29.70 — a 1% spread — would cost $5 for the same service.
Common questions
- What's a fair spread?
- It varies by channel: interbank and good card rates run under 1%, decent online services 0.5–2%, street desks and hotels commonly 3–8%, airports worse. The tool's job is to turn any offer into a comparable percentage — once you see 4%, you can decide if the convenience is worth it.
- Which direction of the rate should I compare?
- Compare like with like: the rate you're offered for your direction of exchange against the current mid-market rate for that same pair, checked at the same moment. Desks widen both sides around the middle, so 'buy' and 'sell' rates each carry their own spread.
- Why do desks advertise 'zero commission' at all?
- Because it works. The margin lives in the rate, where comparing takes arithmetic most customers don't do on the spot. Zero-commission desks are frequently more expensive than desks charging a visible fee at a tighter rate — the transfer-cost calculator adds fee and spread together for exactly that comparison.
What this tool can't tell you
The mid-market rate moves continuously, so a comparison made with an hour-old rate misstates the spread. The tool also can't see a desk's minimum charges or the recipient-side costs of a transfer. It measures one number precisely: what this rate costs against the fair one, right now.
These tools are for education. They work from the numbers you type and cannot see your accounts, verify who owns an address, or account for your circumstances. Nothing here is financial advice.