Currency conversion fee calculator
The true cost of a conversion: the stated fee plus the margin hidden in the exchange rate you were given.
What this conversion actually costs
$235.36
2.35% all in — the advertised fee was 15
- Hidden in the rate
- $220.36
- Stated fee
- $15.00
- Per year at this frequency
- $941.46
| Mid-market rate | 0.66 |
|---|---|
| Rate you were given | 0.64 |
| Spread | 2.2% |
| You receive | 6,425.35 |
- A spread above 1% is where most of the cost hides — the stated fee is rarely the expensive part.
A 2.2% rate margin on $10,000 costs $220 — nearly fifteen times the $15 fee printed on the confirmation.
How this is calculated
How this is calculated
The spread is the fee
The margin is the gap between the mid-market rate and the rate you were given, as a percentage of the mid. On a $10,000 conversion a 2.2% margin is $220, while the advertised fee is $15.
spread = (mid − offered) / midAdd the stated fee back on
The total cost is the spread cost plus the fixed fee. Quoting an all-in percentage is the only way to compare a "zero fee" provider with a 2% margin against a $15 fee at a 0.4% margin.
total = amount × spread + fixed feeWorked example: Converting $10,000 at a 2.2% margin
| Amount | $10,000 |
|---|---|
| Mid-market | 0.6580 |
| Offered | 0.6435 |
| Stated fee | $15 |
| Hidden in the rate | $220 |
|---|---|
| Stated fee | $15 |
| All in | $235, or 2.35% |
Four conversions a year at this rate costs $940 — more than most brokerage fees combined.
What this assumes
- The mid-market rate is the true midpoint at the time.
- The fixed fee is charged in the source currency.
- No receiving-bank or intermediary fees.
- The rate is not re-quoted before settlement.
Where this commonly goes wrong
- A "zero fee" or "0% commission" offer almost always carries the cost in the rate instead, often at 1.5–3%.
- Dynamic currency conversion at a card terminal or ATM — being asked to pay in your home currency — typically costs 3–7%.
- Intermediary correspondent banks can deduct $15–40 in transit, which never appears in the quote you accepted.
Questions
How do I find the real exchange rate?
Search the currency pair on any search engine or a market data site. That is the mid-market rate — the midpoint between what banks buy and sell at. Any rate you are offered below it is where the provider takes its margin.
Why is my bank’s "free" transfer expensive?
Because the fee moved into the rate. A retail bank margin of 2–3% on a $10,000 transfer is $200–300, invisible on the confirmation, against a specialist provider at 0.3–0.6% plus a small stated fee.
What is dynamic currency conversion?
When a foreign terminal or ATM offers to charge you in your home currency. It looks helpful and typically costs 3–7% in the rate. Always choose to be billed in the local currency and let your card do the conversion.
What is a reasonable FX margin?
Under 0.5% all in is competitive for consumer transfers. Around 1% is acceptable for small amounts where a fixed fee dominates. Above 2% you are paying a retail bank spread for a wholesale service.
Does this apply to buying foreign shares?
Very much so. Brokers convert at their own rate on every purchase and again on every sale, so a 0.6% margin on a round trip is 1.2% before any brokerage. Over years of regular buying that dwarfs the trade commission.
Are multi-currency accounts cheaper?
They can be, because you convert once at a chosen moment rather than on every transaction. The saving is real only if the account’s own conversion margin is low — check it the same way as any other provider.
Related tools
Sources
This calculator does arithmetic on the figures you enter. It does not account for tax, fees, or your personal circumstances.
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