How Long Can a Baby Sleep in a Car Seat? (Time Guidelines)

Key Takeaways

Car seats are designed to protect your baby in a moving vehicle and insulate them during a crash, not for extended sleep
Napping in the car or stroller is okay, because it’s supervised sleep. Never use a car seat for unsupervised sleep, like overnight
Babies younger than 6 months should not spend more than 2 consecutive hours in a car seat

Most parents know that the safest place for a baby to sleep is alone on a flat, firm surface with no pillows or blankets. Since car seats are designed very specifically to keep your baby in an inclined position, it makes sense that parents wonder if this is a safe position for their baby to sleep in. The short answer is: it depends.

The length of time, use of proper restraints, and level of supervision are all key factors in determining whether or not your baby is safe to sleep in their car seat. Read on to learn more.

Why Car Seats Are Not Meant for Prolonged Sleep

Car seats aren’t meant for prolonged sleep, simply because that’s not what they’re designed for. They are designed to properly position and restrain your baby while traveling and to cushion them from impact in the event of a crash, not to provide an optimal sleep environment.

Car Seat Design and Baby’s Airway Position

Everything from the pitch of the incline to the positioning of the harness restraints is designed to keep your baby safe in their car seat. The priority is to protect their head and spine in the event of a sudden change in direction or crash impact.

However, for small babies this positioning can put more stress on their airways. Babies who are born prematurely have to pass a “car seat breathing test” before they can be discharged from the hospital for this reason.

What Pediatricians and Safety Experts Say

Pediatricians and safety experts agree that it’s okay if your baby falls asleep in their car seat for short periods of time, like while in the car traveling or in the stroller when the car seat is used as part of a travel system.

However, for babies under 6 months this time period should be limited to less than 2 hours. And even for older babies, they should be removed from their car seats once you reach your destination and transferred to a firm, flat sleeping surface. Babies should never sleep unsupervised in a car seat, like overnight.

How Long Can a Baby Sleep in Car Seat Safely

Young babies should not stay in a car seat for more than 2 consecutive hours. This is known as the 2 Hour Rule, and should be followed until a baby can hold up their head without support and sit unassisted. This milestone can vary by age, but usually happens somewhere between 4 and 6 months of age.

Older babies can sleep for longer, but only when necessary. Once you arrive at your destination, your baby should be transferred to a firm, flat sleeping surface. And never leave your child to sleep in a car seat unattended or unsupervised. A car seat should not be used overnight sleeping.

Risks of Letting a Baby Sleep Too Long in a Car Seat

The biggest risk of letting a baby sleep too long in a car seat is that it can impact their breathing. This is especially true if you unbuckle or loosen the restraints. It also keeps your baby in a cramped position, which can impact their muscular and skeletal development in the long run.

Compromised Airways

Especially for small babies, the position of a car seat can put pressure on their airways. The harness system is designed to fit snugly and keep your baby properly positioned, but many parents might loosen these for a sleeping baby or forgo them altogether if using your car seat for naps outside the car.

This is dangerous, because it means your baby is no longer properly positioned. Their heads can slump forward and make breathing difficult.

Cramped Positioning

Car seats cradle your baby closely for safety, but they also keep them from being able to stretch out and move. It’s important that your baby be able to move freely for proper muscular and skeletal development.

False Sense of Security

Parents naturally associate car seats with safety. When they’re being used for travel, as intended, they are indeed safe.

But they were never designed to be used for unsupervised sleep. It’s important to only let your baby nap in their car seat when you’re able to observe them, like in the car or stroller while on the go.

Safe Practices When Traveling with a Sleeping Baby

There are a few things to keep in mind when traveling with a sleeping baby to ensure your prioritizing safety.

Always Keep Your Baby Properly Restrained in the Car Seat

The harness system is what keeps your baby in a proper position that allows them to breathe easily, even when they fall asleep. This is why it’s important to never loosen the straps or leave the harness unbuckled, just because your baby is napping.

Consider a Bassinet Stroller for Young Babies

If you’re frequently on the go and your baby is younger than 6 months, consider a bassinet style stroller. This allows your baby to lie flat in a safe sleeping position, instead of remaining in their car seat.

Transition Your Baby to a Safe Sleeping Surface

Once you arrive at your destination, transition your baby to a safe sleeping surface like a bassinet or a crib. If you’re traveling, use a pack n’ play or other portable crib.

How Long a Baby Can Sit Safely in a Car Seat Overall

For babies under 6 months of age, they should not be in a car seat for more than 2 consecutive hours. This is regardless of whether they’re awake or asleep. It’s important to keep in mind that the 2 Hour Rule applies when you’re using the car seat with a stroller as part of a travel system as well, and to be aware of car seat mistakes that could compromise your baby’s safety.

For older babies, the guidelines are a bit more ambiguous. It’s still important to give your baby regular breaks from their car seat if you’re on a long trip and, if your baby falls asleep in the car then you should transition them to a firm, flat sleeping surface when you arrive at your destination.

Regardless of age, your baby should never be left sleeping in a car seat unsupervised. This means you should not use one for overnight sleeping—stick to a bassinet or crib instead.

Elevate Your Baby’s Comfort and Safety with Orbit Baby

Orbit Baby’s products are designed with your baby’s safety and comfort in mind. Orbit baby car seats can be used safely from birth for babies as small as 4 lbs.

For parents on the go, consider a travel system that includes a bassinet attachment, like Orbit Baby’s Stroll, Lounge, and Ride Travel System. Being able to transfer your baby from the car seat to a bassinet, where they can lie flat, maintains an optimally safe sleep environment without missing a step.