On the day I departed for Rome, I went to the downtown Boston branch of my bank, Citizens Bank. I was given a rate of 1.4 dollars per Euro. Actually, I think it was 1.41, but anything above 1.4 is moot, as you will see when you continue reading.
While in Rome, I took cash out of an on-the-street ATM. To take out 100 Euros; my bank statement reflects $131.75. However, there was also a $3.95 foreign currency fee. Still, the resulting $135.70 reflects a rate of 1.35 to do the exchange. I would imagine the $3.75 currency fee remains the same even for larger withdrawals; so the exchange rate on the currency was 1.318.
As for my credit card, I used it quite often in Italy. I see on my statement a dinner that cost me 77 Euro. The corresponding charge was $100.67. This represents an exchange rate of 1.307. There is a foreign transaction fee on my statement for $11.46. Since it's a general fee for the entire statement, I can assume it represents the collective foreign transaction fees for all five international credit card transactions reflected on the statement. That would equate to roughly $2.29 per credit card transaction.
Here's a quick summary:
Getting cash from my bank before leaving the United States:
Exchange rate was 1.4 dollars per Euro.
Using my ATM card:
Exchange rate was 1.318 dollars per Euro, plus a $3.95 fee per transaction.
Using my credit card:
Exchange rate was 1.307 dollars per Euro, plus a $2.29 fee per transaction.
The bottom line: The exchange rate is far better for credit card and ATM transactions, compared to going to your own bank to get a cash currency exchange.
It's worth noting that I didn't bother to even try using an overseas exchange counter, like one of those exchange stations you see at an airport or on the street. My assumption is the exchange rates there-- as well as the effective rates when adding in fees-- are pretty high.