If you’re expecting your first baby soon, it’s time to start thinking about car seats.

You may already know that there are two types of car seats for newborns: infant car seats and convertible car seats. Both are safe for your baby, but there are some important differences you’ll want to consider when registering or shopping for your baby’s first car seat. Those differences have to do with size, portability and how long you’ll be able to use the car seat before your baby gets too big.

Here's what parents need to know about both infant and convertible car seats, plus how to decide which one is right for your newborn.

Infant vs. convertible car seats

Really quickly: Let’s go over safety basics for newborn car seats. These rules apply no matter what type of seat you get.

Infants and toddlers should ride in a rear-facing car seat until they reach the weight limit or height limit of their specific model, whichever comes first. You should plan to keep the car seat rear-facing until at least age 2 and maybe even longer, depending on your baby’s growth. Infant car seats and convertible car seats both allow babies to ride rear-facing from day one.

Now, let’s get into the differences between the two.

Infant car seats

Infant car seat pros

  • Infant car seats are generally smaller and more compact. They might be a great option for you if you’re going to make frequent trips with your baby and you need something portable. Infant car seats are also handy if you’re going to be moving the seat from car to car frequently.
  • Parents appreciate that many infant car seats can be used with a travel system. This means the seat can come out of the car and snap into a stroller frame. You can keep your baby buckled in when you get out of the car and start walking around the grocery store or the park. This is a great option for families on the go!

Infant car seat cons

  • The trade-off? Your child will outgrow an infant car seat faster than a convertible one.
  • Different brands and models have different size limits. Typically, infant car seats can fit babies up to around 35 pounds or 35 inches long. Once your baby is too big, you’ll need a convertible car seat to keep her safe while driving.

Convertible car seats

Convertible car seat pros

  • A convertible car seat might be right for you if you want to invest in just one car seat that will last many years. Being able to convert the seat from rear-facing to forward-facing means you can use the same model from the day your baby is born until she’s ready for a booster seat.
  • Convertible car seats are installed rear-facing at first and then “convert” to a forward-facing position when your child outgrows the weight or height limits. Depending on the model, convertible car seats can fit children up to 65 pounds in the forward-facing setting. Some can even be turned into a booster seat for older kids.
  • Convertible car seats also usually have greater weight and height limits for the rear-facing setting than infant car seats do, so your baby can ride rear-facing for longer.

Convertible car seat cons

  • The downside? Convertible car seats are often larger and bulkier than infant car seats.
  • They’re typically not designed to be portable. They don’t have carrying handles like infant car seats, and they’re not designed to be quickly taken out of the car once they’re installed.

Whichever model you choose, always keep safety in mind. You shouldn't use a car seat if it has been in a crash, if it has parts missing, if it has been recalled or if it’s past its expiration date. If there's no expiration date, use six years from the date of manufacture. And if you don't know the history of a used car seat, it's safer to buy a new one. 

Your car seat should meet federal motor vehicle safety standards and have a five-point harness. Look for a label with this statement from the National Highway Traffic Safety Administration. If you can't find it, don't buy the seat!

When to switch from an infant to a convertible car seat

You should switch from an infant to a convertible car seat once your child reaches your infant seat's maximum weight or height, whichever comes first. Most car seats are outgrown when your child's head is less than one inch from the top of the seat, but check your seat's manual to be sure.

An infant car seat’s weight limit is often marketed more clearly (some models include this in the product name), but keep in mind that many children will reach the height limit before they do the weight limit.

Every model is different, but most infant car seats have a maximum weight that’s somewhere between 28 and 35 pounds, and a maximum height between 30 and 35 inches. You can find the limit for your car seat in the user manual, on a label on the side of the seat, or by checking online. Most children will reach one of those two milestones sometime between 9 and 18 months.

Even after you switch to a convertible car seat, you should still keep your child rear-facing as long as possible. And remember, if you ever need help installing any type of car seat, you can find a child passenger safety technician in your area through the National CPS Certification Program at safekids.org.