Currency can be converted using an online currency convert, or it can be performed manually. To use either method, you must first look up the convert rate using an online convert rate calculator or by contacting your bank. The rates charged by your bank may differ from those you see online because banks earn small profits on converts, whereas online rates are the same as those quoted between banks.
In addition, it is important to note that the convert rate you receive when trading one currency against another probably will differ from the rate you will obtain during the actual conversion of one currency into another at a local bank. Traders can access the tight bid-ask spreads that are posted by banks, but visitors to foreign countries who require local currency will pay slightly higher prices for the same currency.
For example, an online EUR/USD (euro against the dollar) may appear as 1.5560 - 1.5563, which means banks are selling to each other at 1.5563, but are buying from each other at 1.5560. The spread of three pips (points) is the profit banks realize for facilitating this transaction.