First of all, let’s make sure we’re on the same page with what a booster actually is!  A booster is a seat where the child sits on it and uses the vehicle’s seat belt as their restraint. A car seat is a seat the child sits in and uses a 5-point harness (car seat straps) as their restraint.

This can be confusing because there are seats that can do double duty — starting as car seats and turning into boosters. With these seats if your child is using the 5 point harness then they are riding in a car seat…and if your child is sitting on the child restraint and using the vehicle’s seat belt across them, then they are riding in a booster.

What does the booster do? A booster positions the vehicle’s safety belt properly on a child. The booster makes sure that the lap belt rests on the child’s lap, over the strong hip bones – and nowhere near the soft belly. The booster also makes sure that the shoulder belt rests between the child’s shoulder and neck

When is it safe to move your child into a booster?

If you can answer “Yes” to ALL the statements below, your child is safe to use a booster:

  • There’s a shoulder AND lap belt (boosters need shoulder belts)
  • The child is at least 40 lbs
  • The child is at least 5 years old
  • The child can sit properly the entire trip without leaning forward, slouching, playing with the shoulder belt, sitting on their knees, etc.

Young children under age 5 or 6 are safer in a 5-point harness car seat. Don’t rush to “graduate” your child to a booster seat. If your child still fits in his 5-point harness car seat, leave him there!

Why shouldn’t my 3 year old 30 pound child use a booster?

The 5-point harness of a forward-facing car seat provides the best protection for pre-schoolers because it not only restricts movement, ensuring that toddlers are in the proper position should a crash occur, but also distributes the crash forces over a larger area of the body when compared to a safety belt and booster seat (two chest straps with the safety seat’s 5-point harness versus one chest strap with the safety belt.). While many booster seats say that they can be used for children weighing as little as 30 pounds, it is best to wait until the child is at least 40 pounds (and has met the other minimums stated above) before using a booster seat.

Do I HAVE to transition my child to a booster once they reach 40 pounds?

No! Many 40 pound children are not mature enough to use a booster seat. If your over-40-pound child is not mature enough to sit properly in a booster – i.e. the child likes to try and lean over to fight with a sibling, pick up dropped toys, hang out the window, play with the seat belt, etc – then this child is NOT READY for a booster seat. This child needs a 5-point-harness that can accommodate a taller, heavier child. Since most kids are too tall (their shoulders reach the top shoulder strap slot) long before too heavy in their forward-facing car seat, choosing a seat with the highest shoulder strap slots will allow your child to use the 5-point harness for longer. The seats that have the highest shoulder strap slots (and both turn into boosters for later on) are the Britax Frontier/Pinnacle Click Tight ($339) and the Chicco MyFit ($199).

When is my child ready to stop using a booster? When can they use the regular seat belt?

There is no magic age, height or weight determining whether your child will be safe without a booster. Because a booster corrects poor vehicle seat belt fit, a child should use a booster until the vehicle seat belt fits him properly. This can be anywhere from age 8 to age 13. 50% of all ten year olds still need to use boosters for proper seat belt fit. Unless you can answer “yes” to all the questions below, your child STILL needs a booster in order for the seat belt to fit correctly–regardless of his height, his age, or his weight.

Also, please note that because boosters work in conjunction with the vehicle seat belt and vehicle seat cushion, an older child may need to use a booster in one vehicle but not in others. Make sure to perform the 5-Step Test the first time your older child rides in a new vehicle.

The 5-Step Test

Put your child in the car and have her sit like an adult, without a booster. Buckle the seat belt over her. Now answer these questions:

  • Does the child sit all the way back against the auto seat?
  • Do the child’s knees bend comfortably at the edge of the auto seat?
  • Does the belt cross the shoulder between the neck and arm?
  • Is the lap belt as low as possible, touching the thighs?
  • Can the child stay seated like this for the whole trip?

If you can answer “yes” to every question, your child is okay to ride without a booster. If you answer “no” to any of these questions, your child still needs a booster in order to be safe.