According to the Centers for Disease Control, the recommended height for children to be able to sit in the front seat of a car is 57 inches tall, or 4 feet 9 inches. Some states, such as New York, permit children to sit in any seat with a booster seat.
Seat belts are designed to fit properly at a minimum height of 57 inches. A seat belt fits correctly when the belt is on the thighs rather than the stomach, and the shoulder belt lies on the chest instead of the neck. The CDC recommends that children sit in the rear seat even after reaching 57 inches.