When a child outgrows a traditional harnessed child car seat, they graduate to a booster seat. Most children reach this transition around 4 years of age. However, it is size, not age that is the determining factor as to what seat is appropriate for your child.
If your child outgrows his seat before age 4, consider investing in a seat especially designed for larger children who are still at a young age. You will know your child is ready to advance to a booster seat when he has reached the following milestones. First, he reaches the top weight or height listed on the seat. Secondly, his shoulders are above the top harness slots. Lastly, his ears are at the top of the seat. If your child meets these criteria, it is time for him to move to a booster seat.
Booster seats raise the child up so the car’s lap and shoulder belts fit. Booster seats are designed with and without backs. Since the straps from the car are to be used, there are no straps that come with the seat. Booster seats are only to be used with seat belts that include lap and shoulder belts. If your car only has lap belts, replace them with seat belts that have a shoulder belt as well. Booster seats should be used until the child can fit properly in a seat belt by sitting on the car’s own seat.