Everything You Need to Know About Child Booster Seats

Learn about high-back and backless designs and which is right for you.

Evan McCausland | 

Feb 2, 2023 | 3 min read

Volvo

Once your child outgrows their front-facing, five-point-harness-equipped car seat, they’re ready to move on to the final car-seat stage: a booster seat.

Meant for in-car use, a booster seat is a portable cushioned platform on which a small child sits to bring their body and a vehicle’s factory seat belt into proper alignment — where the shoulder strap cinches against the chest and shoulder and the lap belt rests along the upper thighs. This ensures that during a collision the belt will work as intended, distributing force across sturdy parts of the body rather than vulnerable areas.

When Is It Time to Start Using a Booster Seat?

Guidelines from both the National Highway Traffic Safety Administration and the American Academy of Pediatrics suggest moving to a booster seat once your child outgrows their front-facing seat. This could be when their shoulders come above the top harness slots, the tops of their ears reach the top of the seatback, and/or their height or weight exceeds the seat’s specified limits. This will likely occur sometime between the ages of 4 and 7. At a minimum, a child should weigh 40 pounds before they trade the five-point harness for a booster and a three-point belt.

What Should I Know When Shopping For a Booster Seat?

There are two types of booster seats: high back and backless. High-back models resemble forward-facing child seats but without the harness. They provide vertical and often lateral support (via side bolsters) for the back, neck, and head, and most have some sort of belt guide that helps you position the seatbelt correctly.

A backless booster seat is also as its name describes. It looks like a chair cushion with attached armrests. These models are less bulky than high-back designs and therefore easier to transport for traveling, carpooling, and ride sharing.

Your vehicle can accommodate either design but only in seats with a three-point seatbelt. (A simple lap belt won’t work.) That said, if you plan to situate your kid’s booster in a seat with a low back or one without a headrest, you should opt for a high-back model to provide better head, neck, and spinal protection. Alternatively, there are two-in-one booster seats that offer both a high-back and backless configuration.

Lastly, before you start shopping, check to see if your forward-facing convertible car seat can be reconfigured as a booster seat. Many can, and it’s often as simple as removing the harness and maybe some padding.

When Is It Time to Move On?

Children may ditch the booster seat once they’re big enough (and mature enough) to use the factory seat belt as intended, with the shoulder strap resting against the shoulder and the lap belt atop the lap. This typically happens between the ages of 8 and 12. At the very least, a child should continue to use this seat until they reach a height of 4 feet, 9 inches. Even then, if they play with the belt strap or slouch in the seat without the booster, they’re not ready to go without it.

Evan McCausland

Car, truck, train, or bus—if a vehicle has wheels, chances are Evan McCausland is interested in it. More importantly, he’s interested in helping others learn more about cars and trucks, especially when it comes time to make a decision on their next vehicle purchase. For nearly two decades, he’s been fortunate to have the opportunity to do just that, writing for major automotive publications, automotive clubs, and automakers alike.