Infant Car Seat Guidelines

Your car seat will be one of the biggest investments you make when preparing for baby. Safety, comfort, and longevity are all factors in determining the best seat for your needs. With the help of this comprehensive guide, we hope you’ll better understand infant car seat guidelines and what to look for when purchasing your first (or third!) car seat. We break down the terminology you may find while researching car seats and helpful knowledge to help you make a sound purchasing decision.
We would like to point out from the get-go that ALL car seats sold as brand new have passed rigorous federal safety standards in crash testing, proper labeling, and flammability. As of 2014, the National Highway Traffic Saftey Administration updated FMVSS 213 to raise the weight limit of child restraint systems from 65-80lbs. Though this new law may not affect your infant, it’s important to keep in mind for future car seat purchases.
Now, let’s take a look at some of those infant car seat guidelines, safety requirements, and additional features you may come across for different car seat models and stages!
Common Terminology
As you’re researching infant car seats and their guidelines, you’re going to see some recurring phrases and terminology. Below we’ve explained the five most common terms you’ll find and what they mean in terms of safety for your little one.
Rear Facing
This direction of the car seat is intended for infants and children up to the age of one year AND 20lbs. Though laws vary by each state, the American Academy of Pediatrics recommends keeping your child rear facing for two years or until they grow out of the height and weight restrictions of your car seat.
Forward Facing
This direction of the car seat is meant for children over the age of two and often lasts until the toddler years. Some smaller children will need to use a backless booster until they reach the height and weight requirements of your state.
Proper Use Clause
Most states will have this in their safety legislation. Essentially it means that whatever the manufacturer specifications are for your car seat, you are required to follow them by law. If a manufacturer says an infant car seat is only good for a child height of 30 inches or a weight of 30 pounds, placing a child who weighs 35lbs in the seat is illegal. If a booster seat says the minimum weight to begin using is 40lbs, it is illegal to use for a child under that weight. Knowing the height, weight, and age requirements for a car seat are the guardian’s responsibility! Please be sure always to read the manual to find this information.
Heather Corley of The Spruce has a fantastic updated article (as of 1/22/18) outlining requirements by state. You can find more information here.
5 Point Harness
The harness is composed of two straps that protect your baby at five protective points on their body. One strap goes over each shoulder, crosses over each hip, and connects between the legs. There is often a chest clip on infant and convertible car seats to ensure the straps stay in the appropriate place. This harness is designed to minimize injury to your child, limiting their forward motion in a collision.
As you research car seats you may also see a reference to the two finger rule or the pinch test. These are reminders for parents to check the proper placement and resistance of the seatbelt in relation to your child’s body. No more than two fingers should be able to fit between your child and their safety harness. Still in doubt? If you can pinch any part of the strap together, it is not secured tight enough against your baby’s body. We used an example from The Mommy Doctor to demonstrate this. This also means ALL bulky layers, like thick winter jackets, should be removed before your child is placed in their car seat to ensure they do not sustain an injury during a collision.
Some car seats, such as the Chicco KeyFit, have incorporated an audible click in their car seat designs. The click signifies the appropriate pressure has been applied to your child’s seat belt.
In rear-facing car seats, it’s important that the top of the safety strap is positioned at or below your baby’s shoulders. Once they transition to a forward-facing car seat, the top of the safety strap should be positioned at or above their shoulders.
LATCH System
LATCH stands for Lower Anchor and Tether for Children. According to the Britax website, most vehicles manufactured after September 1, 2002 will come equipped. The lower anchors can be found between the seat cushions of your vehicle while the tether is often found behind the headrest of the backseat.
For rear-facing car seats, that is the infant stage, the lower anchors are often found attached to the car seat base. For forward-facing car seats, this is the toddler stage, the tether is the most important part of the LATCH system as it prevents whiplash and spinal injuries in case of a car accident.
One of our favorite resources, The Car Seat Lady, has some great illustrations of the latch and tether systems. She also has an interactive vehicle buying guide for cars with three rows and their LATCH systems here. If you’re in the market for a new car and want to find a model designed with your growing family in mind, Carmax released a guide at the end of the year outlining their top vehicle picks for car seat compatibility and installation!
EPS vs. EPP Foam
At some point when you remove the car seat cover for cleaning, you may notice white foam (though colors may vary) lining the inside of your car seat. Depending on the manufacturer, this is EPS (Expanded Polystyrene) or EPP (Expanded Polypropylene) foam. This foam is often what you find in bicycle helmets. Its purpose and design is to absorb the force of the impact in case of a collision. Both EPS and EPP foam are single-impact materials meaning, once they’ve been used in a collision, they should never be used again. Almost all car insurance companies will advise the same after an accident and require you to make a new car seat purchase for reimbursement.
The reason car seats have an expiration date is that this foam and the plastic all car seats are made of naturally degrade over time. This can be due to exposure to extreme temperatures, day to day handling, and constant use by your little one. Sometimes cracks in either the foam or the frame of the car seat can go undetected, so it’s important to inspect your child’s seat during cleaning. Expiration dates can range anywhere from 6 to 8 years depending on the type of car seat and date of manufacture.
EPS foam has been the industry standard for many years, but companies are making the transition to using EPP foam instead. It is a little more elastic than EPS foam and can withstand wear and tear for longer periods of time. The use of one foam over the other is based on manufacturer preference alone. As of 2018, EPP foam is not federally mandated over EPS foam in car seat production.
Given this information, we want to stress the importance of not using second-hand car seats. That is unless YOU know for certain how they were stored over time and can guarantee they were never involved in an accident. Car seats should never be purchased from a garage sale or thrift store unless it is in brand-new condition; meaning all manuals are still attached and straps are secured into place by the original plastic tabs.
The Three Stages
Infant
Convertible
Booster
Often the first stage of car seats, this is recommended for newborns up to one year and have a maximum weight of 30-40lbs.
Features include:
- Handle for ease of carrying.
- Canopy to protect baby from the elements.
- Infant headrest or washable insert for a snug and comfortable fit for your little one.
- Base to be left in the vehicle allowing for easy movement of the car seat in and out of the car.
- Adaptable to certain brands of strollers to create a travel system.
Convertible car seats are transitional seats that can be both rear and forward facing. Recommended for infants and toddlers up to the seat’s height and weight restrictions.
Features include:
- Rated for infants and children anywhere from 4 to 65lbs.
- Rear-facing AND forward-facing configuration.
- Two to six recline positions to keep baby safe and comfortable.
- Adjustable headrest and harness height to grow as baby grows.
- Tether strap for securing the top of the seat to the vehicle’s LATCH system.
Booster seats are the final transition stage. These are designed for children between the ages of 4 and 8 years old.
Features include:
- Weight range of 20 to 100lbs.
- 5 Point Harness and Seat Belt Positioner.
- Head and harness height adjustments to accommodate growing child.
- Tether strap to secure the top of the booster to the vehicle using LATCH system.
- Can be used until your child legally meets ALL age, height, and weight requirements for your state.
Are All Car Seats Made the Same?

This screenshot from the Britax website (a high-end car seat dealer) describing their patented SafeCell Impact Protection technology says it all: “Protect your child well beyond the federal safety standards”.
We’ve stated it before, but we are going to emphasize this again: infant car seat guidelines are federally regulated!!! That means ALL car seats sold as brand new across all manufacturers have passed the same federally regulated safety standards. Just because one may cost more than the other, doesn’t indicate it’s a bad car seat. The lower price point indicates it meets the bare minimum in safety requirements without the additional bells and whistles.
We’re going to make an unexpected comparison to airplanes for a minute in an attempt to simplify things. Planes operated by budget airlines, such as Spirit or Southwest, have passed the same rigorous safety standards as more elite airlines, such as Virgin America or British Airways. When you pay $80 for a seat on a budget airline, you’re getting a baseline of quality and comfort. But when you pay 2 or 3 times more to fly with a more prominent airline, you notice there’s more space to move, wider seats, greater comfort, and other perks to make your overall experience a more enjoyable one.
The same goes for pricing differences in car seats. They’ve all passed the same federally regulated safety testing and standards, but as you move up in price point, you’ll see more features and qualities that make for greater comfort, longevity, and peace of mind.
These features can include a more advanced LATCH system than the required metal hooks (as seen in Chicco car seat bases), more padding in the car seat cover, straps that adjust with the headrest instead of having to feed them through yourself as your baby grows, or additional safety features such SafeCell Impact Protection as seen on Britax car seats.
No matter the price point of the car seat, as long as it is purchased new and is installed correctly, it is designed and certified to protect your child in case of an accident. It’s ultimately your decision whether or not you would like to invest in additional features offered beyond the baseline of safety.
All-In-One Solutions
In recent years, we have seen the release of All-In-One car seat solutions; meaning a car seat that is designed to take you from the infant stages all the way to a backless booster seat for older children. Though with this option, you sacrifice the portability of an infant car seat, you don’t have to invest in several seats through the course of your child’s speedy growth.
One of our favorite options is the Graco 4Ever Extend2Fit All in One Convertible Car Seat. It accommodates children weighing 4 – 120 lb meaning you can use this as soon as baby is born and well until they reach the height and weight laws for your state. They also incorporated an extension panel into their design to provide 5″ of additional leg room in the rear facing position. It’s perfect for keeping your toddler rear facing as long as possible!
Stroller Compatibility
If you’re leaning towards the purchase of an infant car seat, we want to encourage you with one last bit of information! Another reason we favor the infant car seat for the first few months of baby’s life is that they commonly adapt to infant strollers, making them the ultimate on-the-go solution for active parents. Infant car seat guidelines do not require compatibility with a stroller system, so consider this a well-needed perk designed by manufacturers!
Some strollers will require additional accessories to adapt to a specific car seat. A perfect example for this is the Bob Revolution Stroller. A car seat adapter is required to turn this jogging stroller into a travel system. Be sure to keep in mind the weight restrictions for these accessories. Often they are good for the 30lb rating similar to your car seat, but they can have lower weight restrictions depending on the model!
We’ve built an interactive Stroller Compatibility Guide available here. You can find notes within the spreadsheet linking to the specific accessories needed to make your stroller compatible. Don’t see the car seat or stroller model you have your heart set on listed in our guide? Please send an email to hello@thenightlight.com and our team will be happy to do the research for you!
Additional Sources
- National Child Passenger Safety Certification Training Program, Downloadable PDF, March 2014
- The Nightlight Guide to the Best Infant Car Seat, Updated April 2018
- The Nightlight Guide to the Best Convertible Car Seat, Updated October 2017