How old do you have to be legally buy a car?

There's no single answer to the age you have to be to legally buy a car. It depends on the state or country you're in. In many places, you can buy a car at age 16 or 17, but might need a parent or guardian to co-sign the loan or purchase agreement. The minimum age to legally *drive* a car is usually 16, but this doesn't directly correlate to the buying age. You should check the specific laws of your location for definitive information.