Car Seat Safety: 4- to 8-year-old Children

Belt-positioning booster seat

When used correctly, a belt-positioning booster seat prevents injuries in a crash. A booster seat raises your child up so that the vehicle's lap and shoulder belt is properly positioned across your child's hips and chest and away from his belly and neck.

CHOP Research has shown that the use of belt-positioning booster seats lowers the risk of injury to children aged 4-8 years by 45 percent compared with the use of seat belts alone. If the vehicle seat belt is at your child's belly rather than below the hip bones and touching the thighs, he could suffer damage to internal organs and/or a spinal injury if a crash occurs. Until your child is big enough, he needs a boost. Watch the video to learn about installing and positioning booster seats.

Booster seat safety tips

The following are some important booster seat safety tips to help keep your child safe:

  • 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 years of age.
  • You should use a belt-positioning booster seat in the back seat of your vehicle — always with the vehicle lap and shoulder belt. 
  • When using a booster seat, make sure the lap belt lies low and snug across your child’s upper thighs, below the hip bones. The shoulder belt crosses the center of your child’s chest and shoulder and not cut across her neck or face.
  • Never put the shoulder belt behind your child's back or under her arm. Remember the rhyme: "Under the arm, seat belts cause harm. Behind the back, safety will lack."
    • To make the shoulder belt fit better, many boosters come with belt guides (high-back booster seat) or plastic clips (backless booster seat) to help the belt stay on the shoulder. If not, use the shoulder belt height adjusters that are built into your vehicle. We do not recommend non-regulated or "add-on" belt adjusters that can be bought in retail stores because there are no national standards for these products.
    • If your vehicle doesn't have shoulder belts in the back seat, consider having your auto dealer or auto repair shop install (retrofit) shoulder belts, or you can consider using a travel vest, which accommodates children up to 168 pounds.
  • Your child should be tall enough to sit against the vehicle seat back with his knees bent without slouching, and can comfortably stay in this position throughout the trip.

Make sure to follow booster seat safety tips to help keep your child safe.

Types of booster seats

  • Combination seat: A high-back booster seat with five-point harness is called a combination seat. The five-point harness can be used for children who weigh 40 pounds or more. The harness can then be removed and the seat becomes a belt-positioning booster that works with the vehicle’s lap and shoulder belt. Some of these seats can safely accommodate children up to 100 pounds. Be sure to check your safety seat instruction manual or the car seat label for exact weight and height limits.
  • High-back and backless belt-positioning booster seat: A booster seat that uses the vehicle's lap and shoulder belts to restrain the child.
    • A high-back belt-positioning booster seat is useful if your vehicle does not have head rests or has low seat backs. If you use a high-back booster, you might need to remove the vehicle's head rest if it pushes the booster seat forward. Check your owner's manual for instructions.
    • A backless belt-positioning booster seat can be used if your vehicle has head rests or high seat backs.
  • Built-in child restraints: Integrated booster seats are built into the vehicle by a few manufacturers. Some are similar to combination child safety/booster seats. They have a five-point harness system that can be removed when your child reaches a certain weight and used as a booster seat with the vehicle lap and shoulder belt. Some cars have only booster seats. Check your vehicle owner's manual for weight and height information for your built-in restraint.

A wide variety of car safety products, including booster seats, are sold at The Children's Hospital of Philadelphia's Safety Center. For more information about specific safety seat models currently available, visit the American Academy of Pediatrics (AAP) website.

Choosing a belt-positioning booster seat

Follow these suggestions to help choose the best seat for your child:

  • Let your child help you pick out the booster seat. Ask him to try out seats to find one that is comfortable. Teach him how to buckle himself up.
  • Make sure the booster seat meets national standards. The label should say, "This child restraint system conforms to all applicable Federal motor vehicle safety standards."
  • Show your child that the booster will let her see out of the window better and help make the seat belt comfortable. Tell her that boosters are for "big kids." Don't call a booster seat a child's seat.
  • Explain to your child why he is using a booster seat and not just the car's seat belt. Let him know that a booster would help keep him safe if a crash occurs.

Booster seat registration card

Don't forget to mail back the registration card. If you don't, you will not be notified if the booster seat is recalled or has other safety problems.

If you moved since you mailed the card, make sure you call your booster seat manufacturer to update your address.

If you misplaced the registration card that came with your booster seat, please download and complete this form and mail or fax it as instructed.

Download our Booster Seat Safety brochure

Our Booster Seat Safety brochure is available for download.