Complete Car Seat Installation Guide

Read both manuals

Each vehicle and car seat is different. It’s important to follow the instructions in both your vehicle owner’s manual and your child restraint manual. If the instructions differ, contact the car seat manufacturer for guidance.

Choose one installation method

Most car seats can be installed using either your vehicle’s seat belt or the lower anchors, also called the LATCH system. So, which should you choose? Either installation method is safe, as long as it’s used correctly.

Very few car seat manufacturers allow you to use both installation methods at the same time—and most car seats are crash tested with one system, not both. Unless specifically allowed, using them together can be dangerous. The two systems can interfere with each other, changing how the seat absorbs force in a collision.

A properly installed rear-facing car seat protects your child's head, neck and spine during a crash. Because every seat is different, always follow your car seat manual while keeping these installation tips in mind:

• Using your vehicle owner’s manual and car seat manual, choose either a lower anchor or seat belt installation method.
• Perform the inch test to ensure a snug installation.
• Make sure the car seat is centered on the vehicle seat, and no more than 20% is hanging over the edge.
• Adjust the seat to the recline angle recommended by the manufacturer.
• If you’re using a rotating car seat in rear-facing mode, refer to the car seat manual to find out if you should use the tether or not.

For step-by-step instructions, be sure to watch these rear-facing car seat installation videos:

• How to install a rear-facing car seat with a seat belt
• How to install a rear-facing car seat with lower anchors

A forward-facing car seat should move as little as possible during a crash. Correct installation, including the tether, helps the seat keep your child safe. Be sure to:

• Follow your manuals’ instructions for lower anchor or seat belt installation.
• Perform the inch test to ensure a proper installation.
• Adjust the seat to the recline angle recommended by the manufacturer.
• Ensure the tether is attached to the proper anchor for the vehicle seating position. (Tether anchors can be found behind the head restraints or the seatback. In an SUV, be sure you’re using tether anchors and not cargo hooks.)
• For rotating seats, refer to the car seat manual to find out if you need to use the tether or not.

Always use the top tether

The top tether is an important part of installing a forward-facing car seat. It helps reduce forward movement during a crash. Tether anchors are required for vehicle models from 2003 and newer, but not all seating positions have them. Refer to your vehicle and car seat manuals for tether locations and instructions.

To learn more about installing a forward-facing car seat, check out these videos:

• How to install a rear-facing car seat with a seat belt
• How to install a rear-facing car seat with lower anchors

Unlike harnessed car seats, booster seats rely on the vehicle seat belt to protect your child. Think of a booster as a transitional seat that prepares your child to ride with just a seat belt when they’ve reached that milestone.

Using the booster seat correctly helps keep the seat belt in the correct position.

• Be sure your child meets the minimum age, height and weight requirements of the booster seat.
• If you’re using a backless booster seat, be sure your child is in a vehicle seat with a head rest. This helps protect their head and neck in a crash.
• Booster seats must be used with a lap and shoulder restraint—never with a lap-only seat belt.
• The seat belt should come from above your child’s shoulder and cross the middle of the shoulder. It should not touch your child’s face or neck.
• Always buckle loose booster seats in, even when your child isn’t in them. A loose booster seat can cause serious injury in a crash.

Your booster seat manual will let you know how to use it properly. For more information, watch this quick booster seat installation video:

• How to use a high back or backless booster seat

Should I install my car seat in the middle or side seat position?

The best position is one that allows you to achieve the safest installation—and meets your day-to-day needs.

• After recently giving birth, moms may find the side seat much more comfortable to access.
• Depending on your height, the side or middle seat may be easier to secure.
• If you prefer a LATCH installation, you'll need to choose a seat based on your car's anchor positioning.
• You may want to keep side seats clear so older kids can easily get in and out on their own.
• A middle seat installation may provide more leg room for front passengers who are very tall.

If you can achieve a secure fit, either a side seat or middle seat position is safe. The middle seat may provide additional protection during side-impact collisions.

What if my car seat doesn't fit my vehicle?

Different car seats have different footprints and installation requirements. If your current seat doesn't fit well in your vehicle, another model may be a better fit.

Some rear-facing seats can be particularly hard to fit in a small vehicle because they tend to take up more space. If a seat isn't working well for your family, it may be worth exploring other options before transitioning to a forward-facing car seat too early.

Remember: The best car seat is one that fits your child, fits your vehicle and can be used correctly every time.

Do I need to use a car seat base?

Infant car seats often include a separate car seat base that remains installed in the vehicle while the carrier clicks in and out. Many bases have built-in angle adjusters that allow you to achieve the necessary recline angle. This supports your infant's head, neck and spine so they can ride safely in the car. Follow your car seat manual to install the base correctly before using it.

Do I need to register my car seat?

The short answer? Yes. Car seat safety is always improving, and seats may be recalled for a variety of reasons. Registering your car seat is the best way to find out if your child’s car seat has been recalled.

What is a 5-point harness car seat?

A 5-point harness car seat uses 5 anchor points to secure your child: 2 over the shoulders, 2 over the hips and 1 between the legs. This harness helps distribute crash forces across the strongest parts of your child's body. Children should continue using a harnessed car seat until they exceed the manufacturer’s height or weight limits before transitioning to a booster seat.

How do I know my car seat is installed correctly?

Perform an inch test to find out if your car seat is installed correctly. After installing the seat, take hold of it at the seat belt pathway, close to the car seat base. Give a tug side to side and front to back. If you can move the seat more than an inch in any direction, recheck your installation. For rear-facing car seats, check the angle indicator to be sure your infant is riding in the correct recline position.

When in doubt, you can schedule a free car seat safety check with a CPST in your area.

Ready to learn more? Get more car seat safety tips in our Car Seat FAQ.

If your child has an injury or is showing signs of illness, call your doctor or visit an urgent care center. If your child has a life-threatening injury or illness, is having trouble breathing or is unconscious, call 911 and/or visit an emergency department immediately.