What is the difference between convertible and infant car seats?

QWhat is the difference between convertible and infant car seats?

Also I’ve seen references to “all-in-ones” ..? Are these all the same?

AThe Answer

Car Seats 101 – What’s Best For Your Baby: Convertible Or Infant?

And What’s the Difference Between a 3-in-1 Car Seat and a Convertible Car Seat, Anyway?

Just a quick heads up to you new or expectant parents out there. Your child is going to go from looking like this:


To looking like this:


And she’s going to do it a lot faster than you’ll believe! So when you set out to choose a car seat for your baby, you need to consider the potential longer term implications of your purchase and you need to consider the car seat’s safety, installation, and usage specifications for every age and size it may well need to accommodate.

Some parents choose to purchase infant car seats and then “upgrade” later to a car seat that can secure their growing child; some parents choose a seat that can be modified and repositioned in multiple ways over the years to meet the needs of smaller infants and larger little ones. And for some folks, such as nannies or grandparents, who might need a car seat that can handle a range of kids in short order, a car seat that can be quickly and easily adjusted is a must.

First, let’s clear up what we mean when we use the terms infant car seat, convertible car seat, and 3-in-1 car seat.

Once we have our terms defined, we can move on the the process of helping you select the best car seat for your family.

Infant Car Seats
As the name suggests, these car seats are designed specifically to accommodate infants, i.e. babies 0 – 12 months of age. Many infant car seats can safely secure babies weighing as little as 4 pounds, and most all work for kids weighing at least 7 or 8 pounds, usually ranging up to around 30 pounds at the heaviest. Most every infant car seat on the market today can be lifted off its base (and often connected to a waiting stroller), so you can carry a sleeping baby from the car to the house (or store, restaurant, etc.) without waking them and can use the infant car seat as a safe place to secure your child even out of the car.

Convertible Car Seats
As the name makes pretty clear, these seats convert into different set ups. The major feature of a good convertible car seat is its ability to be rear facing and backward leaning while securing smaller infants and to be forward facing and more upright when holding toddlers or larger kids. Most convertible car seats, in their rear facing position, will work for babies weighing up to around 30 pounds. In their forward facing configuration, many of these seats work for kids weighing 70, 80, or even as much as 100 pounds.

3-In-1 Car Seats
While occasionally brands will use the terms “3-in-1” and “convertible” interchangeably when talking about their car seats, let us be clear: a properly defined 3-in-1 car seat does not have a rear-facing option, and thus is not the safest choice for an infant. These seats feature two different forward facing configurations, one with an insert for smaller toddlers, one without as the kids grow bigger, and then can have their back’s removed to serve as a booster seat alone. They are a fine choice for larger kids, but will not serve your kid(s) at all when in those newborn or early infancy days.

So now we know a bit about the types of seat available… next let’s talk about the family

The type or types of car seat (or multiple car seat) your family goes through over the years should be directly impacted by the number of kids you have (or expect), the gaps in their age, the vehicles you own, and… well there are a lot of factors! Let’s just cover the main few issues to help get you thinking.

Is this your first child?
But likely not your last? Then investing in an infant car seat might be a fine idea: a dedicated infant car seat is the safest place for your littlest one to be while in the car, and if it’s likely that two or more kids will be along eventually, it will be worth the price even though you’ll only use it for a handful of months with each kid.

And here’s a tip when it comes to infant car seats: invest in multiple bases if you have more than one car: it’s cheaper than buying two car seats, and will let you transfer the seat itself from vehicle to vehicle.

Is this a second or third kid (or fourth…)?
As the chances grow more likely that this is your last time around the infant lap, you might start to consider skipping the infant car seat in favor of a convertible seat. After all, good convertible car seats are plenty safe for small babies when in their rear facing configuration; just be ready to have to remove and potentially awaken your sleeping youngster rather than lifting out the seat wholesale.

Will the seat have to be moved around much?
If you’re only getting one car seat but have plural cars (or need to occasionally install the seat in the car of a baby sitter, friend, or relative) then you need to consider the size, type, and ease of installation before making your purchase. As crazy as this may sound, some car seats are so large they almost won’t fit in the back seat of certain cars when rear facing (at least not without the shotgun seat pushed far forward). Of course safety has to come first, but there are safer yet more compact options out there, and depending on your car, size may be a major factor.

Also be aware how much space some car seats consume of the seat next to them – many bulkier car seats will leave room for just one other rider on what should be a three person back seat.

So now we know a few things!

Like we know that infant car seats are very safe for smaller babies but will not “grow” with your growing child. And we know that convertible car seats offer the greatest span of use, but may not be quite as secure or comfortable for newborns. And we know that a 3-in-1 car seat is fine for kids ranging from 20+ pounds all the way up to the time when they finish using a car seat, but that a 3-in-1 won’t do at all for smaller infants.

And you know about your current family, your plans for expansion, your fleet of vehicles, another such details that might impact your decision. Now let’s talk about a few specific seats: if you can’t find the right car seat for your needs on this list, at least our breakdowns are sure to help you find one that will!

The Dedicated Infant Seat
The Maxi Cosi Prezi Infant Car Seat

The Maxi Cosi Prezi Infant Car Seat is one of the best-rated infant car seats around in terms of safety, and that’s of course the alpha and the omega of any car seat: its primary job is protecting your kid, plain and simple. It also happens to be very well designed for the comfort of your infant, with excellent padding, several recline settings, and a built-in sunshade. It’s not quite such a comfortable seat for you, however: this thing is pretty damn heavy! 11 pounds might not sound like much, but try adding in a 15 pound (or more) baby and you’ll understand why weight is the main complaint of this car seat’s owners.

Very Safe
Comfortable for Baby
Easily Lifts Off of and Snaps Onto Base

Quite Heavy
Not Compatible With Many Strollers
Pricey for Infant-Only seat

The Takeaway
At the end of the day, your baby’s safety and wellbeing are paramount, and this is a very safe infant car seat. But it is heavy enough to where some smaller parents (or grandparents, baby sitters, etc.) may not be able to comfortably or even safely lift it as its occupant puts on more and more weight, and a safe car seat is no good if you can hardly heft the thing into the car! If you’re not cowed by the weight and you don’t mind a rather hefty price tag (the Maxi Cosi Prezi is usually priced north of $225), then this is a fine choice for your infant.

Note that there are countless infant car seats on the market, and many are perfectly adequate – we’ve chosen this one example to highlight thanks to its safety ratings, but other comparisons you might want to research include:

The Graco SnugRide Classic Connect Infant Car Seat

or the

EvenFlo Nurture Infant Car Seat

Both are well reviewed and well liked by owners, and both cost less than half the price of the Maxi Cosi Prezi.

A 3-In-1 for the Bigger Kids

The Graco Nautilus 3-in-1 Car Seat


If you choose this combination car seat, make sure you like it before the return period is over, because chances are it’s going to be in your car for many, many years. The Graco Nautilus can support kids weighing up to 100 pounds, and for the record that can mean 9 or even 10 years old! (Many kids will have already “graduated” out of a car seat by then, but there’s always a chance you’ll have this thing for a decade, and that’s certainly plausible if you have plural kids.) The Graco Nautilus is (we know we’re beating a dead horse here, but this is a critical point) not acceptable for newborns or smaller infants: it cannot be adjusted to sit rear facing; this is a seat for toddlers and kids. So if you have a toddler or a small kid, here’s the lowdown:

Works For Kids Up to 100 Pounds
Great Low Price
5 Point Harness for Kids Up to 65 Pounds

Not OK for Infants

The Takeaway
If your kid has outgrown their infant car seat (or is on the way to doing so) and you think they’ll be your last little one or that you’ll have a decent gap between kids, then this is a fine choice for a 3-in-1 car seat at a great low price. That affordable price also makes it a good choice for grandparents, other relatives, nannies, or anyone else who might not need a car seat all the time, but wants one with a wide age range when they do.

Our Second Favorite Convertible Car Seat

The Maxi Cosi Pria 70 Convertible Car Seat

Guess what that “70” in this car seat’s name represents? Yep, you got it! This seat is suitable (in its front-facing configuration) for kids weighing up to 70 pounds! And while that might sound impressive… it’s actually pretty much the only reason the Pria is today’s runner up. It’s a comfortable seat with moisture-wicking fabric atop soft padding atop a rugged steel frame, and it can serve kids as small as 9 pounds in its rear facing mode, and of course up to 70 pounds when facing forward. Here’s the 4-1-1:

Very Safe Seat
Comfortable for Little Ones
Adjustable Headrest and Strap Positions
More Compact Than Many Seats

Can’t Accommodate Infants Smaller Than 9 Pounds
Only Fits Kids Up to 70 Pounds

The Takeaway

As you see, the only real drawbacks we find with the Maxi Cosi Pria 70 Convertible are that it won’t work for the smallest newborns (those that weight less than 9 pounds) and will be outgrown well before a 3-in-1 style car seat or even other convertible type seats. As far as your youngsters safety and comfort, this seat is hard to beat for the many months (years, actually) that will fit into it. And hey, it’s even got a cupholder for the little one’s beverage, snacks, or toys. (Of course… many car seats do these days… still a nice touch!)

Our Favorite Convertible Car Seat

The Graco SmartSeat All-in-One Car Seat

See that little distinction there? This is no “3-in-1” car seat; this is an ALL-in-1 seat. That means that rather than simply having three different forward facing configurations, it can accommodate your child all the way from their first days up until they approach middle school! (Provided they haven’t hit that growth spurt yet and outgrown car seats.) The SmartSeat can safely protect infants as small as 5 pounds when rear facing, so even if your little one was born prematurely or is simply very petite, you can bring him or her home in this car seat. It can then undergo a series of conversions that will work until the youngster weighs as much as a hundred pounds! That’s an impressive range indeed. Now let’s talk pros and cons…

Amazing Weight Range of 5 – 100 Pounds
Machine Washable Fabrics
Easily Adjustable Systems
Secure Lock Indicators

A Bit Pricey… But Not Even That Expensive Given Long Term Use!
Uses Lots of Space When Rear Facing

The Takeaway
If you’re only going to buy one car seat, consider the Graco SmartSeat All-in-One Car Seat first! In case we haven’t been clear, its weight range is remarkable and industry leading. Users consistently give the SmartSeat a 5 star rating, and the National Highway Traffic Safety Administration gave the car seat a 5 star evaluation as well. So if you trust thousands of happy parents, the NHTSA, and us here, then this is a car seat not to overlook.

Shall We Wrap It All Up?

Not all car seats are created equal! Infant car seats are safe for tiny tots but are quickly outgrown and relegated to the garage or closet. 3-in-1 style car seats, like the Graco Argos 65 3-in-1 Harness Booster, are great for growing kids but can’t be used for little guys. Some convertible car seats, like the Britax Advocate G4.1 , work for most every age at which your child needs extra support and security in the vehicle, while others are more limited. Which car seat is right for you and your family? Well that’s up to you!