Every time you squish your toddler into his car seat, you wonder if it's time to switch to a booster seat. After all, your toddler meets the height requirements. Plus a booster seat might even allow your child to buckle himself into the seat rather than waiting for your help. But are there disadvantages to switching your child to a booster seat too early? How can you know when the time is right to make the switch?

What is a booster seat?

Unlike a car seat that uses a five-point-harness, a booster seat allows your child to use the seatbelt restraint of your car. Your child can sit on top of a booster seat to "boost" them up to the right height for the seat belt. The seat belts in your car are designed to fit adults, so a booster seat mimics the height of an adult when your child sits in it.

What age can you switch to a booster seat?

It's hard to tell the right time to switch your child to a booster seat. Each child grows at different rates. However, here are some general guidelines that will help you determine if your child is ready to move to a booster seat.

• Your child weighs at least 40 pounds.
• Your child is at least 4 years old.
• Your child will stay in the booster seat the entire car ride with the seat belt properly fitted across the shoulder and below the hips.
• Your child has outgrown the internal harness or height requirements of a forward-facing five-point harness car seat.
  

Advantages of a five-point harness

Although the draw of a booster seat is tempting for both parents and kids, there are some clear advantages to keeping your child in a five-point harness as long as possible. Each time your child graduates into the next level of seat belt usage, they lose a layer of protection. The five-point harness of a car seat fits smaller children much better than a booster seat with the seat belt. As you move your child to a booster seat, they'll be free to move out of a proper seat belt position or even unbuckle the belt more easily.

While the child is sitting in the booster seat, make sure they don't put the shoulder belt behind their back or under their arm. If they insist on doing that to be comfortable, it's best to use a car seat with a harness or a different booster seat with an adjustable shoulder belt guide.

Most kids will find it difficult to will stay in a booster seat the entire car ride and keep the seat belt properly fitted until they're about five years old. There's no rush to move your child from a five-point harness car seat to a booster seat. Instead, let your child grow out of their car seat, then make the transition to a booster seat.

Types of booster seats

There are primarily two types of booster seats you can choose for your child: A high-back booster and a backless booster.

Backless boosters are easy to transfer from one car to another. When using a backless booster, the vehicle must have a seat back high enough to provide support behind your child's head. What's high enough? Your child's ears should be below the top of the vehicle seat or head rest.

Most kids are better off starting with a high-back booster seat. The additional support of the high back helps remind kids to sit correctly. They also help position the seat belt on your child and they support kids who often sleep in the car so they don't slump while sleeping.