Find Out Which Is The Best 3 in 1 Car Seat

Best 3 In 1 Car Seats

Their little girl was sound asleep in the back… then it hit them like a train…

Accidents happen when you least expect them.

There’s only one way to protect yourself and your loved ones by getting the best safety possible. There’s no way of knowing when it will happen. So you have to think ahead.

You’re looking for a 3 in 1 car seat. This is a smart thing to do because you will be saving money in the long run without compromising on safety.


There are so many car seats on the market that it takes a lot of time to get the right one. It’s not uncommon for parents to spend weeks, if not months, of sifting through all the data.

This is the reason why I’ve created the best 3 in 1 car seat article. I want you to save some time and only look at car seats that are the right fit. By reading this article to the end, you will learn what to look for and what to avoid when you’re shopping for a three in one car seat.

Also, you will find the one that fits you the best. Now I won’t leave you hanging stick with me for a bit, and I will share with you what happened in the accident above. Also, I will reveal which car seat was tested in real life and how did it perform.

Let’s get this best article started.

#1 Maxi-Cosi Pria – Best 3 In 1 Car Seat

Maxi-Cosi Pria 85 Best 3 In 1 Car SeatThis incident happened with some friends of ours.

They were on a long road trip. Their son was asleep in the back. Everything looked to be boring and usual.

Then all of a sudden, a tractor-trailer slammed into them from the back. It was traveling at 70 mph. The impact was loud, and the trunk just disappeared. The back window cracked, and sharp glass pieces were flying all around.

The father did its best to keep the car under control. Eventually, he lost. The car started skidding left and right on the road. Eventually, they landed in the ditch.

When things got quiet, they checked on their son. He was safe and sound. Although he was wide-eyed and scared, all the glass shards missed him. He wasn’t hurt.

The Maxi-Cosi Pria 3-In-1 Convertible Car Seat won the Best 3 In 1 Car Seat award.

As you have seen from the accident above, it has been tested in the field by real people. Their son wasn’t hurt. So it’s the safest 3 in 1 car seat you can get.

3 in 1 means that you can install this Maxi Cosi car seat both front and rear-facing. Plus, it can serve as a booster seat later. From 4 to 100 pounds, this car seat will serve your child well. Matter of fact this can be the only car seat that you ever have to buy.

Maxi Cosi has outdone them with the Pria. It has magnetic buckle holders. So when you have to strap your little one in, you won’t have to fish out the buckles under their bum.

The Maxi Cosi Pria deserves the best 3 in 1 car seat award.


It comes with magnetic clasps so no more fishing for the buckles

No straps rethreading ever

It’s easy to clean, and it’s dryer friendly


This is a big seat not meant for small kids or a small car

It’s extremely wide it will take a lot of space

#2 Graco Nautilus Snuglock LX – Best 3 in 1 Booster Car Seat

Graco Nautilus SnugLock LX 3 in 1 Best Harness Booster Car SeatIf you’re looking for the best harness booster car seat, you have just found it. The Graco Nautilus is one of the safest car seats on the market today.

According to Consumer Reports, it’s the highest-rated car seat there. Graco has developed the ProtectPlus system. This offers safety from the front, rear, side, and even rollover accidents. We all know that rollovers are rare, but they contribute the most to road fatalities. So if you can get rollover protection, do it. You will not regret it.

The Graco Nautilus is a 3 in 1 car seat which caters to older kids. This car seat can be mounted in harness mode, high back booster, and backless booster mode. The weight limits are set to 22 and 120 pounds. As you can see, you can use it for many years to come.

And you probably noticed that this will be the last car seat that you ever have to buy.

It has two cup holders, which could be very important for younger kids. They can store drinks in one and toys in the second one. Best of all, these can’t be removed and turned into projectiles.

The Graco Nautilus is at an affordable price. For a 3 in 1 car seat, it’s a bargain without yelling cheap.


It’s super easy to install just listen to the “Click” sound

It’s top-rated on Consumer Reports

Padded side protection for older kids not many car seats offer this


The material stitched on by elastic that par won’t last

There’s no leveling guide, so you have to guess

#3 Graco Slimfit Convertible Car Seat – Best Affordable 3 In 1 Car Seat

Graco SlimFit 3 in 1 Convertible Car SeatMaybe you have a big family and need to fit 3 in a row. Or just maybe you want some extra space for an adult in the back the Graco SlimFit is here for you.

It’s a 3 in 1 car seat. So it will serve your child from 5 pounds all the way up to 100 pounds. That’s some good mileage for the money.

If you want it, this could be the first and last car seat you will ever buy. You can take your newborn home with this car seat because the lowest weight limit is 5 pounds. After that, it will serve you well in the years to come. It can be mounted both rear-facing and in front-facing mode. Finally, it can be used in booster mode.

The biggest selling point for this 3 in 1 car seat has a narrow profile. It takes up less space than other seats.

It’s an older version, so there’s no Clicktight feature. None the less it’s easy to install. Do check the manual first, and if you find some difficulties, there are videos on YouTube.

From all the 3 in 1 car seats, the Graco Slimfit won this award.


It’s a perfect car seat who wants three across

It has everything you need: safety, comfort, and sturdiness

Easy to use no manual threading of straps everything is automatic


You will need to force of Hulk to strap it down right

Not much tilting options if you want to mount it in rear-facing mode

#4 Britax Allegiance – Best 3 Stage Convertible Car Seat

Britax Allegiance 3 Stage Convertible Car Seat The Britax Allegiance is an earlier model from the Britax family. It’s been tried and tested by many families, and it delivers.

It’s one of the most affordable convertible car seats you can get. Let’s talk about safety for a bit. As with all Britax car seats, you’re getting a steel frame. This will keep your little one safe and sound, no matter what happens. There’s a layer of side impact protection.

It can be mounted both rear and front-facing. For many parents, it’s important to keep their child rear-facing as long as possible. With the Allegiance, you keep your little one rear-facing up to 40 pounds. This is quite generous. It’s way over the two-year mark.

Since it caters to younger kids, cleanability is paramount. As you know, Britax delivers on all fronts. The cover can be easily removed, and machine washed. It’s highly suggested to use a gentle program with cold water. The only drying solution is to let it air dry.

For a three-stage convertible, the Britax Allegiance 3 In 1 Car Seat is the best in its class.


It comes with a simple adjustment feature without manually retreading the straps

Great Velcro holder for the straps no more wasting time trying to find it

This three stages convertible car seat saves you money because you buy it once


The manual is confusing you’re better off with YouTube videos

The fabric is not machine washable you can imagine the rest

#5 Graco Tranzitions 3 In 1 Car Seat – Best Budget Convertible Car Seat

Graco Tranzitions Best Budget Convertible Car SeatThis incident happened with a friend of mine. They were going home from ballet class with her daughter. She was occupied with something in the back.

It was their mundane commute. But everything changed when they stopped at that stop sign.

A drunk driver slammed into them from the back at 50 mph. The clash was loud. The trunk simply disappeared, and the back window shattered into pieces. To make things worse, the impact was so strong that the backseat deformed.

After things quieted down, the mother instinctively reached for her daughter. She was scared and wide-eyed. She was unhurt. All glass shards missed her. She was fine.

Even though it’s a cheap car seat, it has done an amazing job protecting the child. It’s super light and easy to install.

It’s a 3 in 1 convertible car seat because it has three uses. You can mount it as a forward-facing harness, high back booster, or a backless booster car seat. The Graco Tranzitions 3 In 1 Car Seat caters to older kids. The minimum weight requirement is set to 22 pounds, and it taps out at 100 pounds.

Besides being cheap and lightweight, it’s a good car seat for traveling and rental cars. It will save you a lot of money and is more comfortable than what you can get from rentals. Here’s a hidden frequently missed benefit. It has a narrow profile so that you can do 3 across with it.

If you’re looking for a safe, budget, and narrow convertible car seat, the Graco Tranzitions 3 In 1 Car Seat is the best choice.


Finally, a super lightweight car seat that’s easy to transition in and out

It has a narrow profile so three car seat can be fitted in the back

The cushion gives extra comfort, so it’s good on long road trips


The armrest feels short you can only utilize them in backless booster mode

It’s not the prettiest car seat around it gives a cheap feeling

Buyer’s Guide

It was an educational journey, wasn’t it? Now I love to over-deliver so I’ve thought about what kind of bonus I can give to makes this article perfect.

Since I’m reviewing so many car seats, it came naturally to give you a free buyer’s guide. To be as consistent as possible, I had to develop my own system. Now I will share it with you, so put it to good use.

Before we can get to the buyer’s guide, there are two hot tips that you have to know before we can go any further.

Hot tip #1

Before you get to the install process, you have to pick the right place for the seat. Not all locations are equal. The safest place for your child is in the middle of the car. I know that’s not doable for everyone. So here’s the second-best solution the seat behind the driver.

Hot top #2

It’s so important to get the right install nowadays. Since there’s a rise in accidents and poorly installed car seat can provide the best protection, and I won’t continue this thought.

Luckily all brands are striving to make the easiest and most effortless car installs. Just in case you want a second opinion, you can reach out to a licensed professional.  And recently, many companies are offering car seat installs for a fee.

Let’s get this buyer’s guide started.


This is the #1 priority for every parent. Here’s some good news. All car seats on the market are safe because they have passed the government tests. The not so good news is that there are few brands that barely cut.

It’s best to steer away from those. I always go with those that went beyond the minimums. As you know, all have to provide front and rear protection. Now there are a few brands that offer side impact protection as well. Typically there are 1 to 3 layers. A handful of brands started to offer rollover protection.

There are very few rollover crashes, but they are the deadliest. So it’s about time that they are offering it.

Size Limits

This is the second item on the list. Since we’re talking about 3 in 1 car seats, these usually cover a wide age range. In this section, I can make some serious money savings without compromising on safety.

As you know, these car seats are not cheap. But if you’re getting it for life, then this will be the only one that you will have to buy. Some go with the other option of buying a new car seat at each milestone. They have their reasons, and we have ours.

Also, in this section, I usually check out the weight of the seat. Typically 3 in 1 car seats are not meant to be hauled around.


This is where the rubber meets the road. There are brands out there that are notoriously hard to get a good install. Luckily for you, I have only selected those car seats that are all too easy to install.

With 3 in 1 car seats, some offer rear-facing mode and others only three options for forwarding facing. Typically you can use the latch system up to 65 pounds, and after that, the seat belt is your best friend.


This is the last item on the list. Since these car seats cater to small kids and upwards, there will be accidents. And we know kids that they can’t live without a mess.

This is why you need to know how easy it is to remove the fabric and how you can wash it. For example, some brands only allow spot cleaning while others only allow hand washing. The more you know ahead of time, the better it is.

This would be my quick and dirty buyer’s guide.

Also read: Best Graco toddler car seat: Top 6 reviews

3 in 1 Car Seat Conclusions

We have reached the end of the best 3 in 1 car seat. By now you should know which car seat is the best fit for you. Now it’s your turn to take action. Last time I’ve checked stocks were running low, so get it fast.

If you have questions or tips, you can share them below.

Frequently Asked Questions (FAQ):

What is the safest car seat on the market?

Currently, the safest car seat on the market is the Britax Advocate.

What is a 3 in 1 car seat?

3 in 1 car seat means that the car seat has three modes. Typically 3 in 1 means that it has rear facing mode for infants, forward facing mode for toddlers and harness mode for preschoolers.

What is the difference between a 3 in 1 and a 4 in 1 car seat?

The difference between 3 in 1 and 4 in 1 car seat is that the 4 in 1 car seat has the booster mode. Typically the 3 in 1 car seat stops at high back booster mode. While the 4 in 1 goes all the way to backless booster mode.

Which car seats didn’t make the best three in one car seat list?

These didn’t make the cut: safety 1st grow and go convertible seat, Diono radian 3-in-1 car seat (radian 3rxt), graco 4ever all-in-one convertible car seat, evenflo symphony 3-in-1 car seat (evenflo symphony elite all-in-one), safety 1st grow and go infant safety seat, nuna rava child safety seats. Are these baby car seats suited for smaller cars? With smaller cars you can use those infant seats that have a narrow profile. The Graco 4ever offers lots of leg room even in belt positioning booster it’s not dependent on the child size. The safety 1st grow and go belt-positioning booster seat doesn’t need a pool noodle for leveling like other seats. The car seat cover is washing machine friendly.

What is the height and weight limit for these best 3 in one car seats?

The height and weight limit for the booster seat is 120 pounds. The rear-facing weight limit for 3 in 1 car seat is 40 pounds with extended rear facing it’s 50 pounds. For booster seat forward-facing mode it’s 120 pounds or 100 pounds if it’s a high back booster seat. As the child outgrows the infant car seat higher weight tolerance is needed that’s when the toddler car seat comes into play. These would be the weight and height limits for the booster seat. The rear-facing weight limit is around 40 pounds for most 3 in one belt positioning booster seats. The top level height and weight limit is set to 120 pounds or 57 inches.

What is the expiration date of these 3 in 1 booster seats?

The expiration date is 10 year. Keep in mind that it’s measured from the date of manufacturing.

What kind of car seat safety standards do these three in one top convertible car seats have?

These top convertible car seat has the most important car seat safety standards. Child safety is the top priority for all parents. Let’s see what kind of child safety features should you check out. First on the list is side impact protection. When T-bone accidents happen the side impact protection does a great job with safety. Next up is easy installation at any years of age. Other factors to consider would be. Energy absorption is important for a baby car seat in rear-facing mode. Finally there’s the easy to adjust harness and headrest plus the harness system (harness holders). These would be the child safety features. For an infant seat the EPS foam and the foam padding is an absolute must. Since crash forces are high these offer the best protection for your little one. The infant support cushion can be removed after your little one reached 11 pounds from the infant car seats. All these car seats provide easy installation to even smaller cars.

Which are the best car seats with 3 in one function to fit three across?

For smaller cars you will need something that has a narrow profile in forward-facing mode and rear-facing seat for the little one.

How do you install these 3 in 1 car seats with easy installation?

After they are a few years old you can upgrade to the harness system. Make sure you install it on the back seat. And make sure you read the manual for ease of use. To install these seats you can use the seat belt or the latch connectors for the installation system. The latch connectors are easy to use and keep your child safe. The seat belt is just as fast as the latch. The car seat installation can be difficult if you don’t check out the instructional manual. So make sure you read the instructional manual. If you’re going with the seat belt installations then don’t forget to use the seat belt lock it makes life easier. As you know seat belts are finicky when you’re installing them. Also after certain years of age the seat belts are the only way to secure your child. The latch system provides easy installation. Also the latch system taps out at 65 pounds. If you want to keep your child safe then follow the guidelines both in rear facing and forward facing mode. Before you start the installation check out the bubble levels to see if everything is in the right place for car trips. These high-back booster seats are known for their ease of use.

What kind of features should you check out with the best three in 1 car seats?

The little one will make a mess no matter what you do and any year old will do it. The car seat cover is easy to remove and machine washable. The cup holders are easy to remove and machine washable. There are multiple recline positions to chose from. Most car seats are coming with multiple cup holder only the infant car seat comes with a cup holder or without them. The car seat cover is nice and plush and keeps you child from overheating. As you know it’s good to keep your little one in rear-facing position as long as possible. The rear-facing position offers the most protection during a crash. Other features include: no rethread harness, harness storage compartment for the harness straps, buckle pockets. The chest clip for the safety seat should be bellow armpit level. Multiple recline positions are great for additional comfort for any years old. Multiple cup holders is great for kids. When it comes to cup holders i always say the more the marrier. The no rethread simple adjust harness height makes the adjusting easier. The car seat cover and the  seat pad is machine washable. We all know that a few year old will make a mess and knowing that the car seat pad is machine washable is a relief. For a 4 year old the harness height has to be adjusted.

What’s the difference between the 3-in-1 car seat and the all-in-one car seat?

The main difference between the 3-in-1 car seat and the all-in-one car seat is that the 3-in-1 car seat is not a lifer. It’s either from infant age up to 50 pounds or 65 pounds. Or they are from toddler age all the way up to older years of age. On the other hand the all-in-one car seat is a lifer it’s from infancy all the way up to 8 to 12 years old. The 3-in-1 seat has a shorter life span.

Last Updated on October 25, 2023 by Brian Beasley

Written by Linda Reid

Hey there, I'm Linda, a mom of three cool kids. I've tried so many car seats, you could call me a "Car Seat Detective." Searching for the perfect car seat can feel like finding a needle in a haystack, but don't worry! I've committed to researching and reviewing car seats that are super safe, cozy, and great for growing kids. Together, we'll find the perfect car seat that keeps your child safe and cozy, and makes you feel like a super-parent!