By Mitch Lipka / REUTERS

(Reuters) – Vacationers planning to go abroad this summer can save big on their foreign currency transactions if they plan ahead.

The best strategy for international travelers is to use a credit card that doesn’t charge extra fees for converting currency, according to a study released today by Card Hub, a web-based comparison site (http://www.CardHub.com) where consumers can apply for credit cards.

Those fees run from 1 percent to 3 percent of transactions, and average 2.8 percent.

Consumers using a fee-free card can save an average of 8.1 percent compared to what they would spend exchanging cash at a bank window, and they can save an average of 16.2 percent compared to the most expensive alternative of all – exchanging cash at an airport kiosk.

Some cards that avoid those fees are the Capital One VentureOne and Venture Rewards cards; The Discover Escape and Open Road cards, and the Chase Sapphire Preferred card. Some premium American Express cards also steer clear of currency transaction fees.

Furthermore, the currency conversion rates that consumers get when they pay for items and services with their credit cards are better than the rates they would get by exchanging cash at a bank window. In some cases, they are so much cheaper that consumers will usually come out ahead even if they use a card that charges a conversion fee, Card Hub says.

The study found that fees charged by banks to convert currency can vary widely. None of the banks surveyed charged as much as an airport currency exchange.

At the highest end of the scale were US Bank NA (14.2 percent more than with a no-fee card) and Fifth Third Bancorp (10.6 percent more), Card Hub says.

Those with the lowest exchange rates were Northern Trust Corp and BMO Harris Bank, which both were using $1.32 to the euro and had no fees.

Card Hub‘s survey of 15 large banks was done using the exchange rate of $1.26 for a euro — the no-fee cards were quoting on June 11. U.S. Bank, the expensive alternative, was charging $1.44 per euro plus a $9.95 fee.

Here are what some other banks surveyed charged:

* Bank of America, $1.33 per euro (plus $7.50 fee)

* JPMorgan Chase Bank, NA, $1.333 (no fee)

* Citigroup, $1.3000 ($5)

* Wells Fargo & Co, $1.33 ($7)

* HSBC Holdings plc, $1.32 ($12)

In addition to Chase, Northern Trust and Harris, other no additional fee banks include PNC Financial Services Group Inc and Capital One. Wells Fargo was charging $12 last year, but lowered its rate this year. Card Hub notes that the bank rates would apply to customers of the banks.

Travelex, the largest operator of airport currency exchanges, was charging $1.45 per euro plus a $9.95 fee, which ends up costing a consumer 14.7 percent more than the no-fee credit card, Card Hub says.

“Exchanging currency tends to be an important pre-trip task for international travelers, but as this study illustrates, doing so is not only unnecessary, but it will also cost you quite a bit of money,” Card Hub CEO Odysseas Papadimitriou said in a statement released with the survey.

“Using a Visa or MasterCard credit card with no foreign transaction fees, on the other hand, allows you to save as well as avoid undue hassle, given that currency is converted automatically whenever you make a purchase.”

He also suggested bringing a debit card with a low foreign transaction rate to access cash as needed rather than carrying extra currency — risking theft and another money-losing exchange at the end of a trip.

It’s also a good idea to notify you bank and credit card carrier that you’ll be traveling abroad, he said.

Lastly, Papadimitriou, suggested rejecting any offer by a merchant to convert a purchase into dollars. That, he said, is usually a ploy to pad the price by providing the consumer with an unfavorable exchange rate.

(Editing by Linda Stern and Leslie Gevirtz)