When Do I Switch to a Convertible Car Seat?

A car seat is one of the most important pieces of baby gear you’ll own, but keeping the rules and guidelines around car seat safety straight can be daunting.

One of the biggest questions new parents wonder about is when to switch from an infant car seat to a convertible car seat. We spoke with Babylist Registry Consultant and Child Passenger Safety Technician (CPST) Rebekah Kimminau on how and when to make the switch.

What Types of Car Seats Are There?

A little bit of car seat research can go a long way when you’re trying to figure out when to make the jump from an infant car seat to a convertible.

What’s the difference between an infant car seat and a convertible seat?

Infant car seats, also sometimes called bucket seats, are made specifically for infants and younger babies. An infant seat can be used from birth until your child maxes out either the height or weight limit—and even though some of the top rated infant car seats can have higher limits, babies still tend to outgrow them usually around one year of age. Infant seats are always rear-facing and click in and out of a base that stays installed in your car.

Convertible car seats can be used with children of various ages and sizes. Convertible car seats start in the rear-facing position and switch to forward-facing once your child has outgrown the seat’s rear-facing height or weight limits. Convertible car seats don’t have bases like infant seats; instead, they use your vehicle’s seat belt or LATCH system for installation. (LATCH stands for Lower Anchor and Tethers for Children and is a system of built-in straps and hooks on a car seat and anchor hardware in your vehicle. LATCH makes car seat installation simpler and safer.) Convertible seats are generally large and heavy and aren’t designed to be moved regularly between vehicles.

Note: There are also all-in-one car seats, which can be used from birth until they’re ready for a booster seat, no switching required. You can see some of the differences (and similarities) between convertibles and all-in-ones in our round up of all the best car seats.

How Long Are Infant Seats Good For?

On average, most infant seats can be used until a child reaches 30-32 inches or 30-35 pounds.

However, every car seat has very specific height and weight requirements (both minimums and maximums), so be sure to check your seat’s guidelines before using it with your baby.

When to Switch from Infant Car Seat to Convertible

According to Kimminau, your child can stay in their infant car seat until they outgrow the seat by either the height or weight restrictions.

“Or is the key word to remember here,” says Kimminau. “It means that even if your little one meets the seat’s weight requirement but is over the height requirement, it’s time to make the switch, and vice versa.”

Most children will outgrow their infant seats by height first.

“While many infant seats are being marketed to hold children up to two years because of higher weight limits (35 pounds and over),” explains Kimminau, “most children will outgrow their infant seats by height long before they reach the weight limit.”

“A good rule of thumb for most seats is that if the top of a child’s head is within one inch of the top of the shell of the seat, it’s time to transition,” she says.

The easiest way to check this is to find a board book that is one inch thick and place it on top of your child’s head while they are properly secured in the seat.

Time to switch? You don’t have to break the bank when buying a new car seat—there are plenty of options for great inexpensive convertible car seats.

How to Choose the Best Convertible Car Seat

You’ve figured out it’s time to make the switch from an infant seat to a convertible, but now what?

First, you’ll need to figure out which of the top rated convertible car seats are best for your child and your family. Here are a few factors to consider, according to Kimminau:

• Safety. All car seats in the US must meet the same government safety standards, and the safest car seat is the one that fits your child, fits your vehicle and can be installed correctly by you every time. Safety extras to keep an eye out for include additional shock absorption, side-impact protection, an anti-rebound bar (a bar that helps halt the rebound of your car seat during a crash and causes the seat to come to a stop sooner) and a stability/load leg (a bar that extends from the car seat to a vehicle’s floor and helps to reduce the amount of force on a car seat and the rebound of the seat in the event of a crash).
• Ease of installation. Many car seats can be installed using your vehicle’s seat belt or the LATCH system. (LATCH is easier.) If you’re using LATCH, be sure you’re within the weight limits of your seat’s LATCH restrictions, and remember to switch over to a seat belt install once you exceed them.
• Fit. Car seats range in size and shape, as do cars. Be sure the seat you choose can be installed correctly in your vehicle and that it fits properly and allows enough room for the driver and other front and backseat passengers.
• Rear-facing weight limit. There’s a growing body of research that proves riding rear-facing is safer for babies and children than riding in a forward-facing car seat. If possible, always choose a convertible seat that has a high rear-facing weight limit so you can extend the opportunity to rear-face for as long as possible.
• Fabric. Consider the durability and washability of the fabric of the car seat you choose.
• New vs. used. Kimminau recommends always purchasing a car seat new if possible. If you do end up selecting a used car seat, get it from someone you trust and be sure the seat isn’t damaged or hasn’t been involved in a crash. Look up the seat’s expiration date and research if the model has ever been recalled. If it’s dirty, closely follow the manufacturer’s rules on how to clean it properly.

When Should You Turn Your Baby Forward-Facing?

When you first make the switch from an infant car seat to a convertible, your baby will be used to riding rear-facing. The good news is that they’ll be able to stay that way.

You should keep your child rear-facing in their convertible car seat until they reach the top height or weight limit allowed by your car seat’s manufacturer. The American Academy of Pediatrics, the National Highway Traffic Safety Commission and many other top scientists, researchers and physicians all agree on the many benefits of extended rear-facing.