How old do you have to be withdraw from high school?

The age at which you can withdraw from high school varies by state and sometimes even by district. There isn't a single national age. However, most states allow students to withdraw once they reach the age of majority (usually 18). Some states may have exceptions or allow it at a younger age under specific circumstances (like emancipation or parental consent). You should check with your high school's administration or your state's department of education for the specific rules in your area.