Ages and stages: What are the guidelines for car seat safety

Car seats and booster seats protect infants and children in a crash, but it's essential to make sure your child is in the right seat. This varies depending on their age and size. It's also critical that the seat is installed correctly.

Car seats and booster seats have height and weight limits, and children should stay in each seat until they outgrow those limits. The back seat is the safest place for children under 13. Airbags are designed for adult passengers in the front seat.

Our experts share tips on how to choose a car seat for each age and stage in your child's development:

Rear Facing:

Infants and toddlers should always ride facing the back of the car in rear-facing car seats. There are a few options when choosing a rear-facing seat:

• They can ride in an infant car seat with a carrier and base system, where you put the carrier into the base. These can only be used rear-facing.
• You can use a convertible car seat, which starts out rear-facing and is eventually used forward-facing. These seats stay in the car, and you lift your baby in and out of the seat.
• A 3-in-1 or all-in-one car seat can be used in rear-facing, forward-facing, and booster positions. Make sure to read the labels and instructions for each stage.

California law requires kids to ride rear-facing until at least age 2, unless they hit 40 lbs. or 40 inches before that. However, 2 years is the bare minimum, and we recommend facing the back until they reach the rear-facing height or weight limit of their car seat.

Rear-facing seats better protect a child's head, neck and spine during a crash. The shell of the car seat cradles the child and moves with them in the crash.

Learn about car seat installation classes available in both English and Spanish at UC Davis Health

Forward Facing:

Once older toddlers or preschoolers outgrow their rear-facing car seat by height or weight limits, they can transition to a forward-facing car seat.

• Forward-facing car seats include convertible or all-in-one car seats that you may have initially used as a rear-facing seat and will now turn forward-facing. You will probably need to adjust the recline angle on these seats to sit up for forward-facing.
• Forward-facing seats also include combination or harness-to-booster car seats, which start with a 5-point harness that can be removed when the child is ready to use it as a booster seat.

Since all of these car seats fit different ages and stages of children, make sure to read the labels and instructions and adjust for each stage.

Request a car seat checkup appointment from UC Davis Health's Injury and Violence Prevention Program

Booster Seats:

After school-age children outgrow their forward-facing car seat with the harness by height or weight and are mature enough to keep their seat belt in place, they are ready for a booster seat.

Booster seats raise kids up so the seat belt fits them correctly. When they are too small for the seat belt, the vehicle seat belt sits on their soft belly and neck.

If a crash happens, we want the seat belt to sit on the strong, bony parts of the middle of their shoulder and their hips.

Younger kids can use a high back booster to help adjust the shoulder belt. The high back is needed for cars without headrests.

Backless booster seats might be better for older kids who are close to transitioning to a seat belt.

For most kids, they will be between the ages of 8 and 12 before they are ready for the seat belt alone.

Transitioning to a seatbelt alone:

To know if your child is ready to transition out of a booster seat, try the 5-step seatbelt test:

1. Back against the seat: Can they sit with their back flat all the way up the seat?
2. Knees at edge: Can they sit with their knees bent comfortably over the edge of the seat?
3. Seatbelt position: Does the seatbelt sit low on their strong hip bones, or does it sit on their soft abdomen or belly? You want it to sit on their hip bones.
4. Shoulder belt position: Does the seatbelt sit in the middle of the collarbone, not the neck or slipping off the shoulder?
5. Stay seated: Is your child mature enough to stay this way the entire ride?

To speak with local car seat experts or make an appointment for a one-on-one car seat checkup with UC Davis Health staff check out the UC Davis Trauma Prevention Program Child Passenger Safety web page for contact information and car seat safety and installation tips.

This blog was reviewed by Jennifer Rubin , Trauma Prevention Program Manager