Can a 4 year old sit in a booster seat?
When your child reaches the highest weight or height limit allowed for his forward-facing child safety seat with a harness, he should use a belt-positioning booster seat until the vehicle lap and shoulder belt (adult seat belt) fits properly, typically when he reaches 4 feet 9 inches in height and is between 8 and 12 ...
How long should a child be in a 5 point harness?
The American Academy of Pediatrics recommends that kids use a car seat until they reach the maximum height or weight for that five-point harness. This is usually not until at least age five. Three-year-olds are not ready to ride in a booster seat, even if they fit within the manufacturer's height and weight guidelines.