What Are the Height & Weight Restrictions for Child Booster Seats in Ontario?

Minimum Requirements

Once your child reaches 4 years of age and weighs at least 40 pounds, she can begin to use a booster seat. The seat raises her slightly so that the seat belt hits her body in the right places. Without a booster seat, the seat belt tends to hit too high on the stomach and comes down over the neck instead of the shoulder. The penalty in Ontario for driving without your child properly secured in your vehicle is a $110 fine and two demerit points on your driving record.

Once your child turns 8 years of age, reaches 80 pounds in weight or measures 4 feet 9 inches tall, he no longer requires a booster seat by law in Ontario. Make sure the seat belt lies flat across his shoulders and the middle of his chest, and that the lap portion crosses his hips and not his stomach. Children should remain in the rear seat of your vehicle until they are at least 13 years old.

Despite the minimum requirements of the law, the Canadian Paediatric Society recommends that you keep your child in a harnessed forward-facing seat as long as possible. Many harnessed seats are now available that will allow your child to stay harnessed until at least 65 pounds. The CPS also recommends that you keep your child in a booster seat until she is 4 feet 9 inches and 80 pounds, with no mention of an age threshold. Some children do not reach these height and weight milestones until age 12.

Booster seats come in two basic styles -- high back or low back. High back booster seats have a seat back and headrest. They also provide extra head and neck protection for vehicles without head restraints. Low back boosters are more compact and portable, and are suitable for use in vehicles with high seat backs and adjustable head restraints.