Why Booster Seats? Booster seats & car seats save kids’ lives

Use the Right Seat. Every Trip. Every Time.

Until your child is taller than 4′ 9″ (generally 8-12 years old), your vehicle’s seat belt will not fit correctly.

The right car seat or booster seat keeps your child in place so that all of your car’s safety features can work correctly during a crash.

The Booster Seat Difference: 45% Reduction in risk for serious injury during a crash among children ages 4-8. After raising booster seat age requirements, five states saw: 3X increased rate of children using car seats and booster seats, 17% reduction in fatal or serious crash injuries among children. The Right Seat. Every Trip. Every Time. Sources: Centers for Disease Control and Prevention and National Highway Traffic Safety Administration.

Make sure your child uses the correct seat belt, booster seat, or car seat for every trip. And when you wear your seat belt too, it sets the example that safety is important.

This crash test shows how a lap belt alone isn’t enough protection for a 6-year-old child during a car crash. Booster seats allow your car’s safety features to be as effective as possible.

Recommended Seat Type by Age (Years): Birth to 3, rear-facing car seat; 2-8, forward-facing car seat; 4-12, booster seat; 8-13+, seat belt.

Seat Types:

  • Rear-facing Car Seat
  • Convertible Car Seat
  • Forward-Facing Car Seat
  • Booster Seat
  • Seat Belt

Buyer's Guide

When shopping for car seats or booster seats, pay close attention to height and weight requirements. Check that your child has reached the maximum height or weight before moving on to the next type of seat. Never use second-hand car seats or booster seats and pay attention to car seat recalls.

When selecting a seat, ask:

  • Does it fit my child? Use the owner’s manual as a guide.
  • Does it fit my vehicle? Your child and all the other passengers must be seated safely when the booster seat or car seat is installed.
  • Is it easy to use? The easier the seat is to use and adjust, the more likely you are to use it all the time.
  • Does it fit my budget and lifestyle? Consider how often you change vehicles, how many children need booster seats, and other factors.

Suggested ages are general guidelines, but height and weight are the most important factors when choosing a seat. The Insurance Institute for Highway Safety Highway Loss Data Institute also conducts booster seat evaluations for additional help.

  • Usually Fits: 29-32 inches and 4-30 lbs. Always check manufacturer guidelines.
  • Children should be in rear-facing seats through at least age 2 and until they reach the manufacturer’s maximum recommended weight and height.
  • It is fine if your baby’s feet touch the back of the vehicle seat or their legs naturally bend while in the car seat.
  • Pros: Portable, attaches to strollers, lifts out of base in the car.
  • Cons: Must be replaced with a forward-facing car seat once your baby reaches the upper limit on weight or height.


  • Usually Fits: Up to 52 in. and 5-65 lbs. Always check manufacturer guidelines.
  • Works as either a rear-facing or forward-facing car seat, based on the child’s size.
  • Keep children in the rear-facing position until at least age 2; use the rear-facing position as long as possible until reaching the maximum height or weight in the manufacturer guidelines.
  • Children’s legs may bend naturally against the back of the vehicle seat when they are in a rear-facing position. This is fine as long as the child is still within the manufacturer’s height guidelines.
  • Pros: Can be used longer with a greater range of weight and height, as the rear-facing seat “converts” to a forward-facing seat as the child grows.
  • Cons: Takes up more room, cannot attach to stroller.


  • Usually Fits: Over 20 lbs., minimum 2 years of age. Always check manufacturer guidelines.
  • May be able to convert to a booster seat when your child is tall enough or weighs enough, but follow the manufacturer guidelines.
  • Note: Children should be kept in rear-facing car seats as long as possible (until they reach the manufacturer’s maximum recommended height or weight).


  • Usually Fits: Children who have outgrown forward-facing car seats but do not yet fit adult seat belts (minimum 40 lbs.).
  • Available in two styles: High-back and No-back. The owner’s manual will help determine the best option for the age and size of your child and the specifics of your vehicle.
  • High-back booster seats can be used in vehicles with or without headrests.
  • No-back booster seats can generally be used where your vehicle has a headrest that fits the child comfortably.
  • How should the seat belt fit when you child is in a booster seat?
    • Lap belt: Low across the hip bones, touching the top of the thighs.
    • Shoulder belt: Across the center of the shoulder.
    • When the child leans forward and back, the belt should unspool easily and retract without leaving slack.

  • Seat belts should be worn by themselves only when they fit your child correctly, which can vary by vehicle. A properly fitted seat belt ensures your car’s other safety features are as effective as possible during a crash.
  • A properly fitted seat belt:
    • Has a lap belt that sits low across the hip bones, not on the abdomen.
    • Has a shoulder belt that lies across the center of the shoulder and chest, not rubbing against the neck or tucked behind the arm.
    • Fits your child when they sit all the way back in the vehicle seat with their knees bent comfortably.
    • Can be worn properly through the entire ride.
    • Is used every trip, every time, by everyone in the car. You set the example.

The Seat Belt Fit Test: Can your child sit up straight? Does the shoulder belt cross the shoulder? Does the lap belt cross the upper thighs? Do your child's knees bend? If not, you need a new booster seat.
Installation Video Playlist

This video playlist from NHTSA includes instructions for installing various types of car seats and booster seats. Use the menu in the top corner of the video player to browse different seat types.

Installation Tips

When installing a booster seat, follow the owners’ manual for your booster seat as well as your vehicle regarding “child restraint systems.” These guidelines will provide instructions on seat placement and angle. Booster seats must be used with a lap and shoulder belt, not a lap belt alone.

In the Seattle area, Seattle Children’s Hospital regularly offers free car seat checks to ensure proper installation and fit.

Specific car seats vary, but National Highway Traffic Safety Administration installation instruction videos offer useful guides for the most common types.

In the car, where should I install my booster seat?

  • Booster seats must be used with a lap and shoulder belt together.
  • If the center of your back seat has a lap-only belt, place the booster seat in an outboard seat that has a lap and shoulder belt.
  • If you do not have a usable lap and shoulder belt in the back, you can use the booster in the front seat with the lap and shoulder belt. Push the front seat back as far as you can. If your car has an air bag, turn it off.
  • If you must use a lap-only belt, your child should wear it low and tight across the hips without using a booster seat.

Which type of booster seat do I need?

  • A no-back booster can be used in cars with headrests in the back seat. If your child’s head does not rest comfortably in the headrest, use a high-back booster seat.
  • A high-back booster can be used in cars with or without headrests.

Source: Seattle Children’s Hospital

Washington Car Seat Checks and Installation Help:

Get free help ensuring your car seats or booster seats are installed and fitted correctly.

Tracking Recalls

Car seats and booster seats may be recalled due to documented mechanical problems, mislabeling that can lead to confusion, incorrect user instructions or other safety concerns.

What Can I Do?

Washington State Law

It’s the Law. In Washington state, you can get a traffic ticket if your child is not properly restrained. Per Washington’s Child Passenger Restraint Law, the vehicle’s driver can get a ticket if occupants under age 16 are not properly restrained. Law enforcement will use the following guidelines to decide whether the child is properly restrained:

  • Children under age 2 must be properly secured in a rear-facing car seat.
  • Children ages 2-4 must be properly secured in a car seat with a harness (rear or forward facing).
  • Children 4 and older and less than 4’9” tall must be secured in a booster seat with seat belt (or continue in harness seat).
  • Children over height 4’9” must be secured by a properly fitted seat belt (typically starting at 8-12 years old).
  • Child restraint system must comply with U.S. Department of Transportation standards and be used according to vehicle and child restraint manufacturer.
  • Children under age 13 required to ride in the back seat when practical to do so.

The above requirements became effective January 1, 2020.

For the best protection, a child should remain in each stage of the restraints until they reach the maximum height and weight based on the manufacturer’s instructions.

Outside of Washington, laws regarding child safety restraints vary by state. The Governors Highway Safety Association offers a state-by-state overview of restraint laws.

Language support

This website is also available in Spanish. Booster Seat information in English, Spanish, Amharic, Chinese, Oromo, Somali, and Vietnamese is available from Seattle Children’s Hospital.


This web site is provided for educational and informational purposes only and does not constitute providing medical advice or professional services. The information provided should not be used for diagnosing or treating a health problem or disease, and those seeking personal medical advice should consult with a licensed physician. No physician-patient relationship is created by this web site or its use. Neither HIPRC, the University of Washington, nor its employees, nor any contributor to this web site, makes any representations, express or implied, with respect to the information provided herein or to its use.