Typically, if you have ZERO ATM fees, you will get around 0.35 to 0.5% better with ATMs than you will cashing 100s at places with good rates. However, if you have ATM fees, they will typically be between 1% to as much as 3% of the transaction. So obviously, even a 1% ATM fee makes the rate worse than the cash rate for changing 100s. Of course, the safety of using ATMs vs carrying lots of cash may make a 1% ATM fee a very reasonable price to pay. But if the fees are as much as 2 or 3%, that starts to get pretty bad.