Separate the exchange rate from visible fees
A conversion can look inexpensive when the visible fee is low, yet still cost more through the exchange rate. Compare the provider outcome with a reference amount, then add every explicit deduction.
Keep the currency direction consistent
Enter both rates as destination currency received for one unit of source currency. Reversing one rate will make the comparison meaningless.
Use a quote or a provider rate
If you enter a quoted destination amount above zero, the calculator uses that amount and derives its effective rate. Otherwise it multiplies the source amount by the provider rate.
The World Bank defines the exchange-rate margin as the percentage difference between a market reference rate and the rate applied to a transfer. It also describes total transfer cost as the sender fee plus the exchange-rate margin. Review the World Bank’s definitions.
Do not count one fee twice
If the quoted destination amount already includes a visible fee, leave that fee field at zero. Add it separately only when the quote is shown before the fee.
Common questions
What is an exchange-rate spread?
It is the difference between the entered reference rate and the effective rate implied by the provider quote. The calculator expresses that difference as both destination currency and a percentage.
Where should I get a reference exchange rate?
Use a reputable central bank or market-data source and record the time. The reference is a comparison point, not a rate you are guaranteed to receive.
Should the visible fee be entered in source or destination currency?
Enter the visible conversion fee in the source currency. Enter the other deduction in the destination currency.
What if my quoted amount already includes the fee?
Set the visible fee to zero so it is not counted twice. Use the quoted destination amount exactly as shown.