How old do you have to be to be alone?

In most countries, someone has to be living with a parent or other caregiver or primary legal guardian until they turn 18 who will generally handle all of their affairs for them.

However, there is an exception called emancipation, more specifically being emancipated from your parent/parents or guardian or caregiver where you are no longer required to be living with them, but the youngest possible age in most countries you can do this is 16 years old, but you have to prove in court that you are capable of living by yourself and don't need your parent or parents or caregiver to do things for you.

If you are younger than 16, than you are just out of luck and will just have to wait until you turn 16.