Here are the minimum age requirements for renting a car in some popular European countries:
* Austria: 21 years old
* Belgium: 21 years old
* Croatia: 23 years old
* Czech Republic: 21 years old
* Denmark: 20 years old
* Finland: 18 years old
* France: 21 years old
* Germany: 18 years old
* Greece: 23 years old
* Hungary: 21 years old
* Iceland: 20 years old
* Ireland: 25 years old
* Italy: 21 years old
* Netherlands: 21 years old
* Norway: 19 years old
* Poland: 21 years old
* Portugal: 25 years old
* Slovakia: 21 years old
* Slovenia: 21 years old
* Spain: 21 years old
* Sweden: 18 years old
* Switzerland: 20 years old
* Turkey: 22 years old
* United Kingdom: 25 years old
It is important to note that these are just the minimum age requirements. Some car rental companies may have higher minimum age requirements, and they may also charge a young driver surcharge. Be sure to compare prices and read the terms and conditions carefully before renting a car in Europe.