Can you be 18 to have a room in a hotel in Europe?

Question

if not, what is the age?

Answer 1

At 18 you are considered a full adult in most of Europe and  you will not have problems booking a hotel room.

Some hotels will accept younger guests too, but not all.

Many young people prefer to stay in hostels, not because of the legal side, but because it is cheaper and often more fun.

If you are younger than 18, you can still stay in hostels, although some will ask you to proof that you have permission from your parents.

Kids as young as 14 do travel without parents on hostel trips.

From 16 upwards you can certainly travel alone.