Properly Secure Your Baby in an Infant Car Seat

You've probably heard that nearly half of all car seats are used incorrectly in some way. Lots of parents don't read the car seat instructions or look at the labels, so it's easy to make mistakes. These simple tips, illustrated with photos, will help you make sure you're buckling your baby up safely in an infant car seat.

The current best practice is to keep your baby rear-facing for as long as possible. You should keep your baby rear-facing at least until age two at a minimum, though.​

Not all infant car seats are the same, so some features may look different on your own seat. Read through the instruction manual before you use it, and familiarize yourself with the seat's features and requirements.


Make Sure the Car Seat Fits Your Baby

Baby in carseat with family in the car
Tetra Images/Brand X Pictures/Getty Images

Not every baby will fit perfectly in every infant car seat. You can find the height and weight requirements for your car seat on the required labels on the side.​

If you're buckling up a newborn, it's unlikely that your baby will exceed the height or weight limits of an infant seat.

If your baby is very small, he or she may not meet the minimum weight requirement.


Set Up the Harness Straps

Most infant car seats have more than one harness height position. Check the instructions to learn how to move the car seat straps to a different harness slot or to a different position using a no-rethread harness system.​

In a rear-facing car seat, the harness straps should be at or below baby's shoulders. To set up a car seat for a baby who hasn't arrived yet, you can usually choose the lowest set of harness slots. Once your baby is born, it's better to actually sit the baby in the car seat and check to see which harness slots work best. Choose the slots that are closest to baby's shoulders ​without being above the shoulders.

If you're afraid you'll get the harness wrong when you un-thread the straps to reposition them, take a picture of the car seat, front and back before you take anything apart.

That way you can refer back to the photos if you're not sure how it should look after adjusting.


Check the Buckle Position

Some infant car seats only have one crotch strap and buckle position. The crotch strap is the portion of the harness that comes up between baby's legs. The buckle itself is on the end of the crotch strap.

Many car seats have more than one buckle position, though, particularly infant car seats with high weight limits. The various buckle positions allow you to move the crotch strap in close to a tiny newborn, and then to move it out later to accommodate a larger infant.

Some buckle positions are changed by taking the strap out of the slot and moving it to a new one. Some have a sliding mechanism or push-button system to adjust the buckle position.

Check your car seat instruction manual for specifics on how to adjust it, and when you should move to the next position.


Loosen the Car Seat Harness Straps

Before you place your baby in the car seat, loosen the harness straps. The most common way to loosen the harness is via a lever or button between baby's feet. Sometimes the release mechanism is hidden beneath a flap.​

On this car seat, you loosen the harness by lifting a flap, pushing on the lever beneath, and pulling out on the harness straps.

If your car seat doesn't have a front adjuster, you'll need to check the instruction manual to find out where you loosen and tighten the harness. Some budget infant car seats have a rear-adjust system.


Place Your Baby in the Car Seat

Move the harness straps to the side and pull the crotch strap and buckle forward before sitting your baby in the car seat. Baby's bottom and back should be against the seat.

For newborns, you may find that there's still a little bit of space between the baby and the crotch strap. You can place a tightly rolled ​washcloth there to help fill the space. If there's a lot of space, double check that there isn't a closer buckle position that you missed in a previous step.

The rolled washcloth trick is widely accepted by car seat safety experts as an appropriate solution to a temporary problem. You should still read through the instructions that came with your car seat to make sure the practice is OK with the manufacturer. You might also find that your car seat has an extra infant insert or some other way to help tiny babies fit properly.


Buckle Your Baby Into the Car Seat

Bring the harness straps around baby's shoulders and make sure the webbing doesn't have any twists in it. You will need to smooth out the harness webbing each time you buckle your baby in because twisted straps are not as effective when it comes to protecting your baby in a crash.

Place the buckle tongues into the buckle housing until they click. Some buckle tongues must be puzzled together in a specific way before you can snap them into the bottom piece of the buckle. Your car seat instruction manual will show you exactly how to work the buckle.


Buckle the Harness Retainer Clip

The harness retainer clip, which is often called the chest clip, is a key part of making sure your baby is properly buckled up in the car. Retainer clips snap together in various ways, so you'll need to check those instructions again to be sure you're securing it the right way.

Once you have the clip fastened, you should slide it into position at baby's armpit level. With a newborn, it can be hard to get the chest clip into position when you don't have much space between the buckle and shoulder pads. It's important to make sure you get the clip up there, though, because it holds the harness straps in the right position to work best in the event of a crash.

You may need to re-adjust the height of the chest clip after you tighten the harness in the next step.


Tighten the Car Seat Harness

Just because the buckles are fastened doesn't mean you're done! Tightening the car seat harness is a very important step in making sure your baby is buckled up properly.

Most car seats have a tail of webbing that comes out of the seat between baby's feet. To tighten the harness, you just pull on that webbing tail. It's easiest to do several short, gentle pulls to achieve the snug fit you want.

When the harness is tight enough, you shouldn't be able to pinch any excess webbing on the harness straps. The harness should be snug against the baby, with no gaps.

If your car seat doesn't have a front adjuster, check the instructions to see how to tighten the harness. Some car seats have buckles on the back of the car seat or knobs on the side that tighten the harness.


Keep Baby Warm Safely

New parents want to shield their babies from rain, cold, and other unpleasant weather. It's OK to add a light blanket to cover your baby, but you must put the blanket over the top of the harness. Never place blankets or thick clothing or winter coats underneath the car seat harness.

Thick padding and blankets under the harness don't allow the harness to fit tight enough to be safe.

A light blanket over the top of the buckled harness then tucked in around your baby, is usually enough warmth for most situations. You might also consider a winter car seat cover if you need to be out and about with baby in severe weather.​

Don't add any other accessories to your baby's car seat unless they're approved by the manufacturer or they came with the car seat. The infant head support, the harness strap covers, and the toy on the carry handle all came with the car seat used in these photos.

Heather Corley is a certified Child Passenger Safety Technician-Instructor.

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Article Sources

Verywell Family uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial policy to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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