But some reckon the euro is worth only 40p, while others are unsure which countries are in the eurozone, the poll by Sainsbury's Bank Travel Money showed.
As many as 23% of the 2,000 people surveyed were under the impression that one euro was worth more than one pound, with 2.4% valuing the euro at just 40p.
Those polled were five times more likely to believe that Croatia used the euro than the existing currency of the kuna.
Around 20% thought Turkey and Switzerland used the euro, while 2.2% reckoned Spain still used the peseta.
Overall, 23% overestimated the value of other currencies against the pound and thought they were being ripped off.
Sainsbury's Bank travel money manager David Barrett said: "It is surprising that there appears to be so much confusion about the value of the euro and also around which currency is used in a number of countries.
"We would urge anyone planning a holiday to swot up on the local currency before they go."