A dynamic currency conversion (DCC) converts an overseas credit card transaction into your home currency. Merchants market DCCs as a convenient way to help travelers understand the cost of a foreign purchase in real time.
However, DCCs are optional, and should typically be declined. They won’t help you avoid foreign transaction fees and may even come with a conversion fee that can be as high as 7 percent to 8 percent of the purchase price. If you want to know the cost of an item you purchase while traveling abroad, a free currency converter calculator" or app can help.