Once your child is taller than 145 cm (4 feet 9 inches), it may be time to move to a regular seat belt. If a child does not yet fit the seat belt as described below, continue to use a booster seat. Your child is safest in the back seat until 13 years old. Children who use an adult seat belt before they’re ready are at risk for injuries to the head, neck, spinal cord, and internal organs. Make sure your child has support behind the head to the tops of the ears.
Your child can safely use a seat belt if:
- they’re at least 145 cm (4 feet 9 inches) tall.
- your child’s knees bend comfortably at the edge of the seat when they’re sitting all the way back.
- the lap belt stays low and snug across the hip bones.
- the shoulder belt crosses the chest and stays between your child’s neck and shoulder.
- your child can sit like this for the whole trip without slouching.
Until your child can meet all five of the above requirements, keep using a booster seat on every ride. Note that a child may meet all five requirements in one car, but still need to use a booster seat in another vehicle.