The 4 Car Seat Stages to Know About In 2024

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Written by: Fatima O. Millers, CPST

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There are 4 different car seat stages that a child progresses through as they grow. Those stages are Rear-facing, Forward-facing, Booster, and Seat belt.

Choosing the right car seat for your child can be a lifesaver. It is crucial to understand these 4 car seat steps to be able to do that.

Also, knowing when to change a car seat is important to ensure that your child is always safe while riding in the car.

Stage 1: Rear-Facing Seats until at least Age 2

The rear-Facing stage is for infants and toddlers and is used facing the back of the car.

Your baby should rear-face from his/her first ride from the hospital until at least age 2 or as long as possible. 

The CHR and NHTSA recommend keeping the child in the rear-facing stage even up to age 4 or until the seat is outgrown.

The maximum rear-facing weight range usually varies from 30-50 pounds. If your child outgrows his/her rear-facing seat, consider upgrading your car seat with one with a higher limit to keep your child rear-facing for longer.

car seat stages rear facing stage

Don’t worry if your child’s legs are crowding when rear-facing. As long as the height limit of the seat is not outgrown, It’s normal and expected when rear facing. 

Children are wonderful creatures and you will see them riding comfortably with their legs crossed, propped up, or hanging off to the side.

Why is the rear-facing stage important?

The head is the heaviest part of toddlers and infants and that’s why they can’t withstand a car crash facing forward.

And a car seat set in a rear‐facing position moves with your child and supports the head, neck, and spine.

The reason why a properly installed rear-facing car seat dramatically reduces the risk of injury during a car crash. 

Type of seats you can use during the rear-facing stage 

During the rear-facing stage, two types of car seats can be used:

Rear-facing only Infant car seats

You can use infant car seats from birth until at least age 2 or when the baby outgrows the weight limit. Infant car seats are designed for the rear face only and cannot be used forward-facing. 

Most rear-facing infant seats have an upper weight limit of between 28 and 35 pounds and an upper height limit of 30 to 35 inches, depending on the model.

Check the limit on your car seat manual and keep track of when your child outgrows these limits.

Convertible car seats

A Convertible car seat is used rear-facing at first and turned over to a forward-facing position when the child is older. 

The car seat manual will tell you when to make the switch and it won’t probably be until your child hits 2 years old or more. 

Stage 2: Forward-Facing Seats with Harnesses until Age 5+

The Forward-Facing stage is for toddlers and young children, and it’s when a car seat faces the front of the car.

When your child outgrows the convertible rear-facing seat (not infant), it is time to use a forward-facing car seat. 

Rear-facing car seats are equipped with a harness and tether in the back which makes them very safe for toddlers and young children.

Providing that the height and weight limits of the seat permit, forward-facing seats can be used starting from age 2 until age 5 or more.

car seat stages forward facing

Don’t rush moving to the next stage, if your child can still ride in a 5-point harness seat. Children can go as far as 65 pounds in the forward-facing harness seat.

When shopping for a forward-facing harness seat, make sure your child is within the weight and height limits of the seat. Also, check if the head is more than one inch below the top of the car seat shell.

Types of seats used for forward-facing stage

There are a variety of seat options that can be used in the forward-facing stage:


Unlike rear-facing infant seats, convertible car seats are bulky and hard to move from one car to another. 

When purchasing the right convertible seat, it can serve both stages rear-facing and forward-facing until the child is 65 pounds or more.

3-in-1 Car Seat

A 3-in-1 car seat can be converted into one of three options: rear-facing with a 5-point harness, forward-facing with a 5-point harness, and a booster seat. 

You can buy a 3-in-1 car seat option and use it during all stages including the forward-facing step. Make sure to read the limit requirements before making the transition into the next stage.

Combination car seat

You can use the combination car seat for two car seat stages: the forward-facing stage with a 5-point harness and top tether and as a belt-positioning booster when the child outgrows the harness by height or weight.

Stage 3: Booster Seats until the Seat Belt Fits (approx. 4’9”)

Booster Seat is for older children and helps to raise them up so that the seat belt fits correctly.

Start using a booster belt-positioning booster seat when your child outgrows the forward-facing harness stage. 

Your child qualifies for a booster seat starting from age 5 or more. Check your booster seat to make sure the child fits in the height and weight limits of the manufacturer.

car seat stages booster seat

Belt-positioning booster seats are used to ensure the correct seatbelt fit. The seat belt should be positioned over the chest and lab

Your child can stay in a booster seat until the lap and shoulder seat belts fit properly. Typically when they have reached about 4 ft 9in tall and are between 8 and 12 years old.

Every booster is different and weight and height ranges vary greatly from one seat to another. So, it’s always good to check the requirements to determine the correct seat for age, weight, and height.

Booster seats require both Lap and shoulder belts to work correctly. If you have only lap belts in your car, consider:

Installing shoulder belts in your vehicle

Using a safety seat with a harness system that goes up to high weights (eg. 120 pounds)

Using a travel vest.

Type of car seats used in the booster stage

High-back boosters 

High-back boosters are useful in vehicles that do not have head restraints/headrests or have low seat backs.

They also provide positioning support for younger kids (e.g., if napping), and may include side-impact protection.

Backless boosters 

A Backless booster is usually less expensive, and more portable. They can be safely used in vehicles with head headrests and high seat backs.

Combination seats 

Combination seats come with a harness that can be used for smaller children until they reach the weight limit and then be used without the harness (built positioning booster seat).

Both options have a maximum limit of up to 120 pounds.

Stage 4: Adult seat belts in the back

The adult seatbelt stage is the final stage and is used once the child is big enough to fit the seat belt properly without a booster seat.

When your child outgrows the limits of a booster seat by height or weight, it’s then time to start using an adult seat belt.

Use the back seat for kids until at least the age of 13.

car seat stages by age seat belt

But to make sure your kid is ready for a seat belt when you need to answer yes to all these 4 criteria below:

Does the shoulder strap cross the center of the chest and rest on the shoulder, not the neck?

Does the lap belt fit low on the hips touching the upper thighs, not the stomach?

Can the knees bend when sitting all the way back in the seat, and feet are flat on the floor?

Check this safety Belt Fit Test and perform it with the child sitting directly on the vehicle seat without the booster seat.

If you answer “NO” to any of these questions, your child is not ready to come out of the booster seat: 

Save this picture on your device or Pinterest to review the stages whenever you need

The bottom line

Knowing and understanding the age limit for each car seat stage is important to make the right choice when buying a car seat for your child.

To know what stage your child fits in, compare their weight, height, and age to the stage’s specific limits. 

Keep in mind that your child should always ride in the car seat that is appropriate for their size – never move them to the next stage too early.

Once you have figured out which stage your child is in, the next step is to choose between the car seat options you have in each stage.

For more information on all seat options, check out our car seat guides and reviews.

Please note: The content provided on Car Seat Parent, including all materials and information, is not intended to serve as medical or health advice. Always consult with ahealthcare professional regarding your specific circumstances, especially when it concerns the safety and well-being of your child in relation to car seat use.

About Fatima O. Millers, CPST

Founder and Editor-in-Chief, Fatima delivers insightful car seat reviews and recommendations. Combining her CPST expertise with an engineering background, her advice is both safe and practical.