Currency Converter
Convert between world currencies using up-to-date rates — with a clear explanation of why the rate you see is not the rate you get.
The rate above is not a price you can get
Published exchange rates are mid rates: the midpoint between the price at which the market will sell you a currency and the price at which it will buy it back. The midpoint is a summary. Nobody trades at it, and no bureau, bank or card will give it to you.
What you get is the midpoint plus or minus a spread, always in the direction that costs you. So the honest reading of any number this page produces is "what the amount is worth", not "what you will receive".
The arithmetic of that is worse than the usual intuition. People carry the idea that a 1% spread costs half a per cent each way. What actually happens is a ratio: you buy at mid × (1 + s/2) and sell at mid × (1 − s/2), so a round trip returns (1 − s/2) / (1 + s/2) of what you had. Taking a mid rate of 1.25:
| Spread | You buy at | You sell at | Round trip returns | Loss |
|---|---|---|---|---|
| 0.0% | 1.25000 | 1.25000 | 100.000% | 0.000% |
| 0.5% | 1.25312 | 1.24688 | 99.501% | 0.499% |
| 1.0% | 1.25625 | 1.24375 | 99.005% | 0.995% |
| 2.0% | 1.26250 | 1.23750 | 98.020% | 1.980% |
| 3.0% | 1.26875 | 1.23125 | 97.044% | 2.956% |
The round trip costs you nearly the whole spread, not half of it. Changing money for a trip and changing the leftovers back is a full-spread transaction, so on a 3% airport rate that is three per cent of everything you converted, for nothing. The zero-spread row is the control: with no spread the round trip returns everything, so the loss really is the spread and not the arithmetic.
Most pairs are two transactions
Reference rates are published against one base currency, so a pair that does not include the base is computed by triangulating through it — dollars to euros to pounds. Taking 1.09 dollars and 0.85 pounds to the euro, the cross rate is 0.779817 pounds to the dollar.
At mid rates that is exactly equivalent to a direct conversion — the euros cancel, and converting 250 dollars either way gives the same number of pounds to the last digit. With a spread it is not, because you pay one on each hop:
| Spread | One hop costs | Triangulated costs |
|---|---|---|
| 0.5% | 0.250% | 0.499% |
| 1.0% | 0.500% | 0.997% |
| 2.0% | 1.000% | 1.990% |
Two hops cost very nearly twice one hop — slightly less, because the second spread applies to an amount the first has already reduced. It is the same compounding as the round trip above, which is why two quite different situations produce almost the same numbers.
Two smaller things this page does
The multiplication itself is usually exact and occasionally not. At a rate of 1.0937:
| Amount | Converted | Converted back | Exact? |
|---|---|---|---|
| 1 | 1.093700 | 1 | yes |
| 10 | 10.937000 | 10 | yes |
| 100 | 109.370000 | 100 | yes |
| 1000 | 1093.700000 | 999.9999999999999 | no |
That is ordinary binary floating point rather than anything to do with money, and rounding to pence hides it completely — every row above agrees once rounded to two decimals. It is the reason financial systems hold amounts as integer minor units rather than as decimals: the drift is invisible at one conversion and is not invisible at a million.
And the other: this page, unlike nearly everything else on this site, has to ask a server for
its numbers — it fetches them from api.frankfurter.dev when you convert. That
is unavoidable, because a rate is not something you can derive, and it is why the notice at the
bottom of this page says a request goes out rather than claiming everything stays in your
browser. Tools here that make no network request say so instead, and the difference is
deliberate.
How to use
- Pick your currencies and enter an amount.
- Read the converted figure at the mid-market rate.
- Expect to receive less than this in practice.
- Compare the total cost of a transfer, not the rate alone.
Frequently asked questions
Why is the rate I actually get worse than this?
Because this is the mid-market rate — the midpoint between what buyers and sellers are quoting, and the rate banks trade with each other at. Consumers are quoted a margin either side of it, and that spread is where most of the cost of a currency exchange sits.
Where is the cost hidden?
In the spread more often than in the stated fee. A transfer advertised as fee-free frequently applies a worse rate instead, which can cost considerably more than a visible fee would have. Comparing the amount that actually arrives is the only reliable method.
What is dynamic currency conversion?
When a foreign card terminal offers to charge you in your home currency. It sounds helpful and is almost always worse, because the merchant's provider sets the rate and takes a margin. Declining and paying in the local currency is nearly always cheaper.
How often do rates change?
Continuously during market hours, and major currencies move constantly. Rates shown by any converter are a snapshot, and for a large transfer the movement between checking and transacting can exceed the fee you were comparing.
Why do airport exchanges cost so much?
Because they have captive customers and high fixed costs, so their spreads are dramatically wider than elsewhere — often several per cent either side. Exchanging a small amount for immediate needs and using a card afterwards is usually far cheaper.
Should I rely on this for a real transaction?
No. It reflects reference rates for information, and the rate you are actually offered depends on your provider, the amount and the timing. For anything substantial, get a firm quote showing the amount that will arrive.
🌐 This tool looks up results using the free Frankfurter exchange-rate API. The word you enter is sent to that service to fetch results; nothing is stored by this site.