How big do you have to be to no longer sitin a car seat?

Children typically transition out of a car seat when they reach a height of 4 feet 9 inches (145 cm) and are between 8 to 12 years old, depending on local laws and regulations. They should also be able to sit comfortably with their back against the vehicle seat, knees bent over the edge, and use the seat belt properly. Always refer to local guidelines for specific requirements, as they can vary by state or country.