Exchange rates are always changing. To know if you’re getting the best exchange rate possible, you will have to compare rates. Look up the current foreign exchange rates online — at XE.com or directly at the Federal Reserve — to determine how much the U.S. dollar is worth at your destination, and ask your bank for their specific currency exchange rates. Compare these rates with other banks, credit unions or online bureaus, and determine which institutions will give you more bang for your buck overseas.