In Depth Baby Product Reviews Led by a Pediatrician

How to Choose a Convertible Car Seat

A Step by Step Guide to Picking the Right Seat for Your Family
How to Choose a Convertible Car Seat
We've tested over 70 car seats, including crash testing, to help you determine which car seat is the best for your baby, toddler, or child.
Credit: Abriah Wofford
By Juliet Spurrier, MD & BabyGearLab Team
Saturday May 29, 2021

After spending tens of thousands of dollars crash testing the car seats we review at a certified testing lab, we know that while many products look similar, they are not equal, and all offer a very different user experience. This buying guide is designed to help parents assess and filter the variety of convertible car seats on the market by guiding what they should look for in a car seat and why.

We also suggest parents read our best convertible car seats review to learn which models impressed us during testing and why. If you are having trouble understanding car seat installation or want to make sure you aren't making any common installation mistakes, you should also read How to Avoid Infant Car Seat Installation Mistakes.

convertible car seat - we are not big fans of a one-and-done approach to car seats and...
We are not big fans of a one-and-done approach to car seats and think an infant car seat should be used until your little one either grows out of it or ages out according to manufacturer directions.
Credit: Abriah Wofford

Why Buy a Convertible Car Seat?

While we feel parents should purchase and use an infant car seat while your baby is small, you will need to acquire a convertible option after your baby outgrows their infant seat. This change happens when your baby reaches somewhere between 9-12 months of age, depending on your particular car seat and how fast your baby grows. We suggest you keep your baby in their infant seat until they transition in the 9-12 months' age range or as their height starts to push the infant seat's maximum length. You should check weight capacity too, but more often than not, it is the height limit that will force the switch to a convertible seat.

Height and Weight Limits

Most of the seats in this review claim to be suitable for children from 5 lbs up to 40-80 lbs and height of 40-57 inches tall, depending on the seat. However, we think the design and features of an infant seat are better suited for younger babies, and parents should avoid convertible car seats until their baby reaches at least 9 months or has exceeded the maximum height or weight limit for their infant seat (height being more likely).

Choose a Seat that Lets Your Baby Stay Rear-facing Longer

Studies have shown that keeping children rear-facing longer is much safer than switching them to forward-facing. The longer a seat can sit rear-facing, the better. All of the options in this review can remain rear-facing until the baby is at least 40 lbs, with two seats offering a 45-pound limit. The Clek Foonf and Graco Extend2Fit both work rear-facing up to 50 lbs (a big selling point for these products).

Experts Recommend Remaining Rear-facing Until at Least Age 2
A study of 15 years of traffic injury data published in 2007 about Injury Prevention concluded that placing children age 1-2 years of age in the rear-facing position resulted in 5.3 times lower risk of death or serious injury compared to a forward-facing position. Please keep your baby rear-facing as long as possible.

So, are the specifications for the car seat's rear-facing capacity a concern? Or are the front-facing limits more critical? Well, both are important, but if we had to pick one, we'd choose the rear-facing limit given the significant increase in the potential safety of children sitting rear-facing. The longer a child can sit rear-facing, the better. Even if your child needs to scrunch their knees and have less legroom, it is still safest to be rear-facing as long as they are within the height and weight requirements of the seat.

Height Limits Typically Matter Most

A general rule of thumb for these seats is that many children might reach the height limit before the weight restriction. However, this is not a hard and fast rule, so parents should keep in mind the limits on their seat concerning the growth of their child as both are equally important in keeping children safe while riding in a vehicle.

Types of Car Seats

There are primarily two types of car seats (not counting top-ranking booster seats), the infant car seat and the convertible car seat. Both options typically work with infants, and they have similar features and functionality, but they are not the same. There are pros and cons to type, and we explore that in more detail in our best infant car seat review (especially why we feel even top-ranking convertible car seats are not appropriate for infants). However, all parents will need to use a convertible seat at some point.

Despite the manufacturer's marketing that sometimes allows for the use of convertible seats for infants as small as 5 lbs, we think you should wait to use them until after your baby has outgrown their infant-style seat. While parents might want to cut corners and save money by limiting the amount of baby gear they purchase, we do not think your child's safety seat is the right place to cut corners. We strongly recommend the purchase of an infant and a convertible seat.

The Safety 1st onBoard 35 Air
The Safety 1st onBoard 35 Air
These photos show an infant car seat (above left) and a convertible-style seat (above right).

Infant Car Seats

  • Separate Bases/Detachable Seats — An infant seat has a carrier portion that can detach from the base that remains in the car. The carrier can be used to carry a baby from one place to another and clicks onto the base for vehicle travel. Being able to transport the baby from place to place while leaving the base in the car gives parents increased freedom and allows the baby to remain sleeping while parents run errands. These carriers can also be attached to a compatible stroller for more convenience on the go. Many of the best strollers offer car seat adapters, or you could try a car seat frame stroller. We find being able to click the carrier into a stroller the easiest choice.

  • Canopy
    convertible car seat - the b-safe 35 has a very nice looking canopy
    The B-Safe 35 has a very nice looking canopy
    Credit: Abriah Wofford
    Infant car seats traditionally offer a canopy to block the sun and other elements. Conversely, convertible seats don't have sunshades, and parents should not create one on their own for safety reasons.

  • Lower Weight and Height Restrictions — Even though some of the infant seats will work up to 40 lbs, their range is still smaller than the convertible car seat that often works from 5-65+ lbs depending on the product. This limited weight range is a result of the carrier being specifically for little bodies, as opposed to a design that tries to work many sizes without fitting any of them well. It is this factor that makes an infant seat perfect for newborns and younger babies and the type of car seat we recommend for infants.

convertible car seat - the allegiance is a convertible car seat with better than average...
The Allegiance is a convertible car seat with better than average comfort and quality.
Credit: Abriah Wofford

Convertible Car Seats

We recommend that babies transition from an infant car seat to a convertible seat at about 9 to 12 months old or when they reach the height or weight limitations of their infant seat. The term "convertible" derives from the seat's ability to be used in a rear-facing position and then "convert" to a forward-facing seat for older/larger children. Being able to use a convertible seat with an infant may tempt you into considering a convertible option as your only car seat, but we urge you not to take a "one and done" approach to finding the the best car seats.

BabyGearLab Recommends Infant-Specific Car Seats for Infants
We do not recommend using so-called "all-in-one" car seats, which are specified to support a wide range of ages, in some cases from infants to pre-teen kids. We believe that infant car seats are the best choice for newborns because they are more convenient and provide a design specifically with smaller bodies in mind. This type of seat fits infants better, including positioning them better for breathing and sleeping safely. We recommend switching from an infant seat to a convertible seat at 9-12 months or when the baby outgrows their infant seat, as identified in the owner's manual. Similarly, we prefer convertible seats (designed more specifically for the 9+ months age range) over the "all-in-one" seats, which may attempt to span from infant to pre-teen booster seat range.

convertible car seat - the clek foonf
The Clek Foonf
Credit: Abriah Wofford

Know the Basics

While all the seats available for purchase in the US meet or exceed federal safety requirements, they are not equal in their crash test results, design, ease of use, or functionality. We will cover the features and performance metrics commonly considered when looking at different seats.

Crash Tests

As you might expect, crash test results are a key metric in the performance of car seats, and thus help differentiate between products. Every car seat must be able to pass a Federal crash test safety standard, with random products chosen by the National Highway Transportation Safety Administration (NHTSA) for testing each year. Each selected seat goes through crash testing in a facility that is designed to simulate actual head-on collisions using a crash sled seat and crash test baby/toddler dummies. These tests collect data generated by G-force sensors located in the test dummies that measure and record the amount of force exerted on the dummy baby's head and chest. This test is a 30 mile an hour crash simulation.

We work with the same testing facility as NHTSA to run the same simulated crash tests for each seat we review for comparison purposes. For each crash test, there are sensors in the head and chest of a crash test dummy buckled into a car seat and placed on the "sled." The sled is used to simulate the forces in an actual car crash, and the sensors record the forces on the "child's" body during the simulated crash. We used a forward-facing Hybrid III 3 YO Part 572 P dummy (3-year-old test dummy) in our commissioned crash tests, because NHTSA crash injury studies have shown that the risk of injury is higher when children are forward-facing, and the heavier 3 yr old test dummy provides a more strenuous test of the seat's ability.

Understanding the Head Injury Criteria (HIC) Score

The Federal safety standard developed by NHTSA uses a factor for scoring called the Head Injury Criteria (HIC) score. This score is the likelihood of injury arising from an impact presented measurably. All of the seats must obtain a HIC score of 1000 or lower to pass the Federal requirements. The further a score is below the Federal HIC maximum of 1000, the better it performed (similar to how a lower score in golf is better).

When analyzing crash test results, we ranked seats by the percentage that each result is below the NHTSA maximum of 1000 HIC (above). We focused on how large a margin of protection each product offers below the Federal maximum 1000 HIC. One could consider the car seats with lower HIC scores as providing an additional margin of protection compared to the competition.

Understanding the Chest (g) Clip Score

The same crash dummies include sensors in the chest region to measure impact forces in the chest. The results from the chest sensors are used to calculate the Chest (g) Clip result, which is the value that attempts to measure the likelihood of injury to the heart, lungs, and other organs located in the chest. To pass the Federal safety requirements, all of the seats must achieve a score less than 60 for the Chest (g) Clip (once again, lower numbers are better).

We looked at the percentage below the Federal maximum Chest (G) Clip score of 60 that was achieved by each seat in this review (above). As we did with the HIC scores, we focused on how large a margin of protection each product provided below the score of 60, Federal maximum Chest (G) Clip score. Seats further below the Federal maximum chest score have a more significant percentage difference, and one could consider them as potentially providing an additional margin of protection.

convertible car seat - we contracted with the same national testing facility used by the...
We contracted with the same national testing facility used by the National Highway Transportation Safety Administration (NHTSA) for crash tests, and also obtained NHTSA's crash test data for analysis. Above you see the Phil and Teds Alpha seat on the test sled with a 12 month old crash test dummy strapped in.
Credit: MGA Research

The good news is the Federal requirements ensure that all the seats sold in the US provide at least a minimum level of protection. Therefore, all the products available for purchase can be considered safe.

While each seat meets the minimum Federal safety requirements, some have managed to pass the tests with better results than the others. In our review of convertible seats, you will see that we have combined crash test data we commissioned with similar data obtained from crash tests commissioned by NHTSA. The tests run in the same manner, at the same facility, so we can analyze them side-by-side to demonstrate how each seat compares to the others and the Federal Maximum for allowable G-forces.

Some seats performed better in crash tests, so we gave higher scores to those seats with the assumption that they offer an extra margin of protection based on crash test results. We believe this matters and deserves to be a factor parents consider when deciding which seat to purchase.

Proper Installation
It is not enough for you to purchase and use a car seat. You must install and use the seat properly and consistently to help ensure safety. Injury or death can potentially occur in an auto accident if a car seat installation or the child restraints are not correct.

We like the way the seat fabric on the Clek is tucked into the shell...
We like the way the seat fabric on the Clek is tucked into the shell offering a smooth transition and sleek look
The Roundabout has the EPP foam that we prefer because it is more...
The Roundabout has the EPP foam that we prefer because it is more environmentally friendly and doesn't off gas
This Peg seat uses EPS foam for energy absorption during a crash
This Peg seat uses EPS foam for energy absorption during a crash

Side Impact Protection (SIP) Claims: Buyer Beware

The photos above show a few of the side impact features marketed by the manufacturers of some of the seats we reviewed. In order from left to right, they are the Clek Foonf with a steel frame for additional SIP, and the Peg Perego Primo Viaggio Convertible that claims "adjustable" SIP.

Because there is no agreed-upon definition of SIP, we aren't sure exactly what all of the claims of SIP mean, and little information is provided to support or explain each manufacturer's claims. Clek Foonf offers more information and transparency on their website than any other we were able to find, including video and results of their side-impact crash tests. Still, overall, transparency is surprisingly lacking across brands.

Currently, there is only a suggested plan for a potentially regulated side impact protection (SIP) testing. However, at this time, there is no regulation testing or common language agreement that determines what to test, how to test it, how to interpret results or how companies should define the terms, or what kind of claims they can make. All of the seats in this review claim SIP in the design of their seat or testing process, but the term itself is somewhat ambiguous, as it means something different depending on which manufacturer is making a claim. For example, Maxi-Cosi cites independent tests they paid for to determine the efficacy of their design in the case of a side collision. While Graco also claims independent testing for SIP, but their definition and test results only cover keeping your child contained in the harness in the event of a side collision. We think most parents would assume that keeping a child retained in the seat by the harness is an essential function of a car seat as opposed to a unique SIP feature. Therefore, we suggest that consumers remain skeptical about any SIP claims given that there is no set standard on what it means or how one claim compares to another.

convertible car seat - the arb like the one seen here on the marathon clicktight arb is...
The ARB like the one seen here on the Marathon ClickTight ARB is supposed to limit or prevent car seat rotation that can happen during a crash.
Credit: Abriah Wofford

Extra safety features are always a bonus, and we welcome useful and tested safety additions that improve products. However, we think parents should be aware of what appears to be some "Safety Washing" happening in the industry concerning the marketing of side impact protection and other features that claim additional protection. Given that there is no industry standard for SIP and other features, and all the manufacturers seem to mean something different, it results in words that have no meaning in and of themselves. This issue requires that parents do further research to determine what manufacturers mean when they claim side impact protection, whether their design or unique feature has undergone testing, and what the tests include. That is a big responsibility to dump on parents, and often the information is not available or accessible (trust us, we looked).

We feel manufacturers use SIP and other safety features as a marketing tool to increase product interest. We'd like to see an agreed-upon standard for these claims that force manufacturers to focus on engineering designs that provide value and that parents can easily compare. To determine what manufacturers mean by SIP and other safety features and their testing process (if any), we tried to find compelling information or evidence related to their claims. We failed, which means we can't compare the features or even discuss them with clarity.

For the time being, we came up short in our efforts to find credible information or evidence to support the claims.

convertible car seat - the honeycomb base on the boulevard is designed to help absorb...
The honeycomb base on the Boulevard is designed to help absorb impact forces in the event of a crash.
Credit: Abriah Wofford

Forward Facing Crumple Zone

The Clek Foonf claims to have a forward-facing crumple zone designed to help absorb the impact of a collision to help protect the child in the seat. It is the only product in the review that has this kind of design or makes this sort of claim; they are also one of the few to post their testing results online for transparency. The Britax seats all claim an "energy-absorbing base," with something they call "safe cell." This feature may be similar to the Clek claim, but once again, without an agreed-upon definition of terminology, it is hard to say what each means or if and how testing was done to support the claim. We have no way of knowing how well these features work, or if they work predictably in an actual crash scenario as opposed to a simulated crash test.

convertible car seat - the britax emblem has an alloy frame you can see in this photo.
The Britax Emblem has an alloy frame you can see in this photo.
Credit: Abriah Wofford

Seat Construction

Every seat consists of similar kinds of materials and basic designs with a few standouts and variations. The majority of the seats have a hard plastic outer shell with dense foam padding as the second layer. A few of the seats also have metal frame components or features that offer increased shell stability that potentially improve seat performance in the event of a crash (though this is difficult to prove in standard tests). The final component is primarily for comfort and includes a layer of padding and fabric that gives the seat its overall look and helps position the baby properly in the seat. Many seats also offer an infant insert pillow. This insert is a positioner that helps smaller bodies fit properly in the seat and within the harness. The insert fits above the fabric cover and is removable when your baby grows bigger, or it is no longer needed. Some of the seats also offer padding or "head wings" around the head area. Presumably, this is for impact protection and possibly comfort; some manufacturers explicitly state this is the purpose of the wings, while others refrain from saying anything outright. The lack of manufacturer clarification makes it difficult for us to tell if the feature is intended to truly improve safety, or give the illusion of improving safety.

We believe that the differences in seat construction that matter are those that reflect in crash test performance, as well as those that impact the baby's overall comfort.

convertible car seat - the back of the chicco plastic shell is smooth and easy to clean. it...
The back of the Chicco plastic shell is smooth and easy to clean. It has a middle storage compartment for the tether strap that keeps it out of the way nicely
Credit: Abriah Wofford

External Shell

The external hard shell is the first line of defense in an accident, as it provides structural support and contains the energy-absorbing hard foam molded to the inside. The construction and design work similarly to a bike helmet, by using an exterior hard plastic shell combined with a layer of energy-absorbing hard foam placed between the shell and your head.


There are two basic kinds of foam in a typical convertible seat.

The Graco has a thick layer of EPS foam in the head region of the...
The Graco has a thick layer of EPS foam in the head region of the shell for energy absorption in the event of a crash
The Emblem uses EPP foam for impact absorption. This type of foam...
The Emblem uses EPP foam for impact absorption. This type of foam does not off-gas and is somewhat more flexible than the traditional EPS foam.
  • Hard Foam — In our review, every one of the convertible seats has foam as their primary energy absorbing material which helps keep your baby safe in a crash. This foam is either made of Expanded Polystyrene (EPS) (above left) or Expanded Polypropylene (EPP) (above right). EPS is the more common type and is somewhat of the industry standard and found in the majority of seats we tested. Alternatively, the Britax seats use EPP foam. We like the EPP better and feel it has a slight edge over EPS because it is somewhat forgiving when bent or pressed on, where EPS will break or deform, and it doesn't off-gas like EPS, which we prefer. The EPS foam, comparable to the foam found in most bike helmets, is common for impact protection applications. The greater difference between seats is how much foam they have and where it is inside the shell of the seat. A few seats have foam inside the entire shell, while others had more foam in the torso and head region with little to no foam in the bottom of the seat.

convertible car seat - the manufacturer of the maxi-cosi claims the headrest on the seat...
The manufacturer of the Maxi-Cosi claims the headrest on the seat provides additional side impact protection, but it is difficult to know what this means exactly
Credit: Abriah Wofford
  • Soft Foam — We tested some seats that provided a softer foam around the head portion of the seat. Good examples of this are the Chicco NextFit or the Peg Perego Primo Viaggio Convertible. Both offer a significant amount of additional soft foam around the head area. Soft foam doesn't offer much regarding impact protection in a crash, but it does offer extra comfort in everyday use. Alternatively, the Maxi-Cosi Pria 70 has a soft foam head pad surrounded by a plastic bag they call "Air Side Impact Protection." The manufacturer claims this feature tested has been tested by an independent lab to determine its ability to decrease injuries related to side-impact crashes. However, this type of functionality is not the norm, and most of the soft foam on seats is either for comfort or to mimic the look of impact resistance.

Anchoring the Car Seat

There are two different methods used to secure a car seat in a vehicle. We will provide you an overview of each, including the most common reasons to use one over the other, or when you might need to use one over the other based on manufacturer guidelines. You can find more information about installation in our article, How to Avoid Infant Car Seat Installation Mistakes.

Read Your Vehicle User's Manual
To properly install your car seat, you need to read not only the car seat user's manual but your vehicle user's manual as well. Why? The vehicle manual is the overriding authority on how to install the car seat and supersedes the car seat manual if the two directives conflict. The vehicle manual is especially important when determining how to install a car seat based on your child's weight. Some car seats require a change from LATCH anchors to seatbelt installation when your child reaches a certain weight. However, your vehicle manual will also have limitations on how much weight can be attached to the LATCH anchors. So if your car seat manual says the seat can be installed using LATCH up to 60 lbs of child weight, but your vehicle manual shows a limit of 50lbs, then you must switch to the seatbelt installation at 50 lbs, not 60.

convertible car seat - this diagram showing latch system lower anchors appears in graco's...
This diagram showing LATCH system lower anchors appears in Graco's car seat manual. Unlike most other manufacturers, Graco documents in their manual that their seats can be LATCH-connected in the center position so long as your Vehicle Owners Manual allows use of the center seating position and the anchor spacing is 11" or greater between the inner LATCH connectors on the left and right side. Unfortunately, most car manufacturers don't allow the use of the inner LATCH anchor points to place a seat in the center.
Credit: Graco

  • Installation using LATCH connectors — Beginning in 2002, the majority of cars in the United States have the mandatory LATCH (Lower Anchors and Tethers for CHildren) on the left and right rear seat positions (not the center seat). This type of connection was created to provide a more straightforward method of attaching car seats to vehicles. We recommend using LATCH when it is available since it is usually the best and easiest way to ensure a tight, secure connection.

convertible car seat - rear facing installation of the clek using the vehicle belt is...
Rear facing installation of the Clek using the vehicle belt is almost as easy as the LACTH, with both requiring use of the same belt path
Credit: Abriah Wofford

  • Installing with a Seat Belt — You can install all the seats using the vehicle seat belt through the designated pathways provided on the seat. Some products have built-in lock-offs while others do not. We found the lock-off usually makes this process easier. Only a minority of vehicles offer LATCH connectors for the vehicle center seat, so a seat belt might be your only option if you want to use the center seat. Also, once your child reaches a certain weight, the seat belt installation often becomes your only install option, as the LATCH system will become unsafe due to the combined weight of the baby and car seat (see tip above).

Vehicle center seat installation is worth considering:
Placing the car seat in the center position can reduce injury by more than 40% compared to installing the seat in a side location.

During our installation testing, we found significant differences between car seats regarding ease of installation with a seat belt depending on the vehicle we were using. Parents who plan to use this location exclusively may want to install their seat of choice in this position to ensure that a good fit is possible before choosing to keep it (Amazon has a great and easy return policy).

convertible car seat - the forward-facing installation of the clek foonf for kids over 2...
The forward-facing installation of the Clek Foonf for kids over 2 years old using the vehicle belt is very secure feeling and easy to accomplish.
Credit: Abriah Wofford

Both methods of installation are possible whether the seat configuration is rear-facing or front-facing. Depending on the laws in your area, children need to be restrained rear-facing up to a certain age or weight range. We recommend you keep children rear-facing as long as possible (within the guidelines of the seat) because it is safer for children in the event of an accident. The choice of how to install is somewhat up to you and what works best for your car, but all seats will eventually need seat belt installation because the LATCH method has weight restrictions.

convertible car seat - to find the right angle for installation the graco has a rolling...
To find the right angle for installation the Graco has a rolling ball level that needs to be in the green zone for proper installation
Credit: Abriah Wofford

Level Indicators

Each seat we tested has a level indicator to help parents confirm when its installation angle is correct. While they don't all look or function the same, they all provide similar information and guidance.

The level indicator on the Primo is a line on the side of the seat...
The level indicator on the Primo is a line on the side of the seat that should be parallel with the ground when installed correctly
The bubble level indicator on the Chicco is easier to use than the...
The bubble level indicator on the Chicco is easier to use than the line indicator on most of the competition.
The photos above show different level indicators we found on the seats we reviewed; in order from left to right: Peg Perego Primo Viaggio Convertible, and the Chicco NextFit.

Some level indicators are plastic molded lines on the seat, or a line on a sticker stuck to the shell side. The level line should be parallel to the ground after installation, and it is best to observe by standing back from the vehicle. Some indicators look more like a traditional level you'd find in construction with liquid and a bubble, or a small ball that rolls inside a plastic casing that indicates the seat is installed at the correct angle range when it falls within a pre-marked area in its path. Parents must use the level as instructed in the user guide with their product.

convertible car seat - the boulevard has an easy to adjust, non-rethread harness height...
The Boulevard has an easy to adjust, non-rethread harness height adjustment that work smoothly and is easy to operate.
Credit: Abriah Wofford

Shoulder Height Adjustment

Adjusting the shoulder height of the harness on a car seat may not sound like a big deal until you have to do it. Being able to alter the harness quickly and easily means your child will be using a correct fitting harness at all times. Avoiding changing the harness height because it is convoluted or difficult to operate could lead to improper restraining in the seat. Not using the harness or seat correctly could lead to injury or possible death in the event of a crash, so this is an important feature to consider on any seat.

convertible car seat - you can see the slots on the back of shell on this graco where the...
You can see the slots on the back of shell on this Graco where the shoulder straps can be threaded through and attached to a splitter plate on the back for height adjsutment
Credit: BabyGearLab Staff

Rethreading the Harness to Adjust Height (yuck!)

Rethreading harness straps to adjust shoulder height is the most challenging method of adjustment in the seats we reviewed. Rethreading requires removing the harness straps from a connector on the back of the seat and unthreading the straps from the current slots through the back to move them to higher slots. The process itself isn't that difficult, even though it is convoluted. However, you usually don't notice you need to adjust the straps until your baby is in the seat. This process means you will need to remove your baby from the seat and possibly the seat from the car to adjust. Then you will need to reinstall the seat before you place your baby inside and get on your way. We worry that some parents will procrastinate, making adjustments for this reason. This hassle could lead to a cycle of forgetting to do it time and time again, leaving your child driving around in a poorly fitted harness. Do NOT do this!!

convertible car seat - the harness height adjustment on the peg perego primo viaggio has an...
The harness height adjustment on the Peg Perego Primo Viaggio has an easy pull tab to operate with no rethreading of straps necessary. This is one of the easiest adjustment options in the review.
Credit: Abriah Wofford

Easy to Adjust Harness Height (Non-Rethread)

The easiest to change, and thus our favorite seats, are those whose height can move without the need for rethreading. This design means no splitter plate, no shifting the straps from one slot to another, no removing the baby from the seat. This kind of adjustment can happen on the fly as soon as you notice the harness needs changing. It is a quick and relatively painless process that requires either pushing a button, pulling a tab or moving levers in, and then pulling the headrest/shoulder portion of the seat up to the required height. The Peg Perego Primo Viaggio Convertible, Britax Boulevard ClickTight ARB, Britax Advocate ClickTight ARB, Britax Marathon ClickTight ARB, Britax Emblem, and the Britax Allegiance all have non-rethread harness systems that are easy to adjust and nicely designed. These were not the only options with this feature in the group, but they are the ones we liked the best.

convertible car seat - the harness release button on the chicco is visible and located on...
The harness release button on the Chicco is visible and located on top of the padding. It does have a little lip on one side to help deter little ones from playing with it
Credit: Abriah Wofford

Harness Tightening and Release

Once the shoulder straps are correct, and your child is buckled in, the entire harness tightens by pulling on the strap that trails from the foot of the seat. This process should be easy, and in theory, it is, but not all tightening straps are as easy as others.

You will know that the harness is tight enough when you are unable to pinch any harness fabric between your fingers. This test is often called the "pinch test."

Most of the harnesses we tested loosen by pressing a button near the foot of the seat, while others worked by lifting a small lever in the same location. The button or lever should be somewhat stiff to operate to prevent little hands from pressing the button. However, they shouldn't be so difficult to use that an adult can't do it with one finger. Some seats have buttons that are visible on top of the seat fabric, while others have the adjustment hidden under padding and material to help little ones avoid temptation (out of sight, out of mind). The Britax Boulevard ClickTight ARB, Britax Marathon ClickTight ARB, and the Britax Advocate ClickTight ARB have an indicator click sound to tell you when the harness is tight enough, though we still recommend you use your best judgment and check the harness before relying on an external system.

convertible car seat - the buckle on the evenflo tribute lx is one of the easiest in the...
The buckle on the Evenflo Tribute LX is one of the easiest in the group to use. The sides pop out on their own when the button is pressed
Credit: Abriah Wofford


The buckles on the majority of the seats we tested are so remarkably similar we can't help but wonder if some of them come from the same assembly line. Many were easy enough to use, and while there is a pressure metric they need to meet, some were too stiff and hard to operate. If you have any thumb strength or structural hand issues, this might be more important to you than it is for others.

convertible car seat - the evenflo isn't the easiest to install with latch or with the...
The Evenflo isn't the easiest to install with LATCH or with the vehicle belt
Credit: Abriah Wofford


While the weight of the carrier in our review of infant seats was important because you need to transport the carriers from place to place, the weight of the convertible seats is less important in our minds because you won't be carrying them around that often. The Clek Foonf is a very heavy seat at 38 lbs and 6 ounces; it is cumbersome to carry and more than a handful. However, given that you will rarely be moving it or transporting it, we don't feel this is a deal-breaker or high on the consideration list for most parents. Alternatively, the Evenflo Tribute LX is the lightest.

Other Features

Sometimes the biggest differences between seats are smaller details. In a product genre where so many of the seats are similar in structure and function, the details are the only thing that helps differentiate them from each other. With gear that is so heavily regulated, it could be difficult to tell one product from another, or for parents to decide why one is better than another without considering the features that make them stand out.

convertible car seat - the rear facing clek foonf has a recline adjustment attachment and a...
The rear facing Clek Foonf has a recline adjustment attachment and a anti-rebound bar, as well as an under the seat belt pathway that includes a belt lock off. It is the most innovative seat in the review and includes a rigid forward facing LATCH system.
Credit: Abriah Wofford

Anti-Rebound Bar

While the jury is out on the efficacy of the anti-rebound bar offering additional protection, general physics seems to support the claim that it does. This bar works on the rear-facing seat and prevents the seat from dramatically flipping back against the vehicle seat back in the event of a crash. It is the back and forth motion that causes head and neck trauma in a collision, so less movement theoretically means fewer injuries. Even though we like the idea of the bar, we think that currently there is not enough information available for caregivers to believe that the absence of this should be a deal-breaker. For the time being, we think it is a potentially useful addition to an otherwise high-scoring seat, like the bars found on the Clek Foonf, Britax Boulevard ClickTight ARB, Britax Marathon ClickTight ARB, and the Britax Advocate ClickTight ARB. However, we wouldn't overlook a high-scoring product without a bar in favor of a lower-scoring option that has one. Luckily, these seats earned higher scores in our review, so you can purchase a high-scoring product that also has a rebound bar.

convertible car seat - the latch storage are hard plastic pockets on the each side of the...
The LATCH storage are hard plastic pockets on the each side of the Chicco seat base. They are a little awkward to get the anchors into correctly, but they work well once they are properly in place
Credit: Abriah Wofford

LATCH Storage

If you use the seat belt to anchor your seat to the vehicle instead of the LATCH connectors, it is useful to have a spot to store the unused anchors. Unlike infant seats, where the anchors could get in the way of proper attachment of the carrier to the base, the anchors on the convertible seats are more of a nuisance than a potential hazard. Not all of the storage options are great, and we prefer the choices that keep the anchors attached to the shell body, so they don't come loose. Chicco NextFit has interesting plastic side pockets, which are sort of hard to use but keep them out of sight. It probably isn't necessary, though, and any seat that keeps them connected to the shell seems to work fine. Clek Foonf has rigid LATCH anchors that pull back under the seat and rear-facing anchors that tuck under the seat bottom.

convertible car seat - the user manual for the peg perego fits in a designated storage...
The user manual for the Peg Perego fits in a designated storage pocket with a clear door that is easy to use and well placed. It is highly unlikely that the book with be damaged or lost with this storage method
Credit: Abriah Wofford

Manual Storage

On each seat, there should be a spot to store the user's manual. You should have easy access to it in case you need it, but it shouldn't be where little ones can find it or where spilled items and vomit can reach it. Onboard storage helps keep answers at your fingertips to improve overall use and safety. It is essential to use the storage space as intended, so you aren't caught without the manual when you need it. Some of the seats store the manual under the padding where the child would sit, which seems like a poor location and one where it could easily get damaged, though this is better than areas where children can find the manual and destroy it before you notice. If you lose the manual or it does get damaged, most are available online, or you can order a new one from the company. It is far better to do the extra work to get a manual than it is to guess specific installation or design information about your seat.

How do I decide which convertible car seat is best for my child?

With so many options and features to choose from, the decision on which car seat to buy can feel daunting. We've broken the process down into steps that help you determine what to consider when deciding which option is best for you and your child. While there are several excellent high-scoring products in this review, your particular needs or limitations might find you choosing a different model that works best for you even if it didn't win an award in our tests.

Step 1: Consider Where the Seat Will Go --Installation

As previously discussed, where you plan to install the car seat may impact which product you choose to purchase. Where and how you plan to use the seat might also influence you. Your usage pattern can make the difference between which option best meets your needs and which will be frustrating to use. Given that more than 80% of car seats have been shown to have at least one serious problem with installation, choosing an option that is easy to install in the location or locations you want will help keep your baby safer.

convertible car seat - the evenflo is the lightest seat in the group and one of the most...
The Evenflo is the lightest seat in the group and one of the most narrow at just over 9 pounds and 17 inches
Credit: Abriah Wofford

Urban Parents

If you reside in a major city and will need to transport your little one in a cab or Uber, you may want to look at some of the lighter weight seats. You may also want to do this if you travel frequently and plan to lug a car seat through the airport or on a train. Some of these seats are heavy, and this should be a factor for parents who won't be installing the seat in their car and forgetting about it. The Evenflo Tribute has high marks in crash testing, and at just over 9 lbs you will have an easier time carrying it than you would the Clek Foonf at over 38 lbs in its rear-facing configuration, or the Britax Boulevard ClickTight ARB at over 28 lbs.

Center or Side?

Will your seat be installed in the center seat or on the side? Some vehicles do not offer LATCH connection points for the center seat, so you will want to check your vehicle for anchor points. Alternatively, you can install the seat using the belt only, and we found during testing that many of the car seats feel very secure installed using a lap-only belt, and some were even easier to install with the vehicle belt than with LATCH.

Research shows a 43% lower risk of injury for car seats secured in the center, but the center location is only safe if you properly anchor the seat. The research also shows that more than 80% of car seats have a minimum of one serious problem with the installation. Therefore, we suggest parents take the ease of installation as seriously as we do.

We think it is worth noting that 61% of us parents, place car seats on one of the side seats. The side seat is more convenient for getting the child in and out of the vehicle, and it is the only option for families with multiple children or those with cars built before 2002.

Installing the Car Seat Safely
Making mistakes when installing a seat or securing the baby in the seat is common. Because of this, we have dedicated a separate article to this topic. It is crucial that car seats be correctly used for them to work properly. For this reason, we advocate parents consider ease of installation and ease of use as critical factors in their buying decision.

convertible car seat - the britax boulevard clicktight is one of the easiest seats to use.
The Britax Boulevard ClickTight is one of the easiest seats to use.
Credit: Abriah Wofford

Step 2: Ease of Use

Because installing your seat is likely to be only an occasional process for most parents, it is the daily ease of use that will impact your experience and the overall safety of the car seat. Getting your child into and out of the seat, as well as strapping them into the harness, are activities you will need to perform daily. How difficult these activities are will quickly become more important to you than how difficult it is to get the seat anchored into the vehicle.

Ease of use varies from seat to seat with scores between 4 and 8 in our testing. Chances are you have a few seats on your list after considering installation locations and how easy it is to install. Finding the seat or seats in this list that are also easy to use should help narrow the options further. All of the Britax options earned a high score of 8 for ease of use. Check our ease of use ratings to narrow your list down. The Evenflo Tribute LX and Peg Perego Primo Viaggio Convertible scored 7s in this metric, making them each a second place for ease of use.

Step 3: Crash Test Performance

All the seats in this review have passed the minimum requirements for crash tests as outlined by federal guidelines. Therefore, all of the seats offer a basic level of protection, but some perform significantly better than others, and you can consider them as offering an extra margin of protection compared to other seats.

convertible car seat - the chest sensor data for the evenflo compared to that of the clek...
The chest sensor data for the Evenflo compared to that of the Clek that has the lowest recorded G forces in the chest sensor during crash tests
Credit: BabyGearLab, MGA Research

Many parents might consider crash test performance to be the most critical factor in choosing a seat. However, because installation and ease of use impact your ability to use the seat correctly, which influences the overall safety, we believe you should consider both of those before the actual crash data. Given that over 80% of parents install or misuse their seat, it matters little how safe a product is if you don't use it correctly. After finding a seat that is easy to install and use, then it is crucial to find one that will function well in the event of a crash after you install it correctly and strap baby in according to the instructions.

To evaluate the crash test data of each seat we review, we analyzed their crash test results to compare how each performed in comparison to the federally required minimum score. Also, we assessed how well each seat performs compared to the other products in the review. Now that you have narrowed down your list to a few finalists, you can use our crash test analysis to choose the seat that offers an extra margin of protection for your final selection.

Car Seats Expire
The foam used to construct car seats has an actual shelf life, so after a certain period, you should no longer use the seat, and it should be destroyed. If you choose to use a hand-me-down car seat, you need to ensure it has not already expired and that it won't expire in the 9 to 12 months that you will need it. Also, it is important to retire any car seat involved in an accident. Even if the seat appears to be uncompromised, you should still discard it.

convertible car seat - several new convertible options were added to this review giving you...
Several new convertible options were added to this review giving you more information on potential competitors than ever before.
Credit: Abriah Wofford


Purchasing a convertible seat does not need to be a daunting experience despite the plethora of options on the market. With a few key considerations and a review of the details on how each seat compared to the rest, you have all the information you need to determine which seat will work best for your family. We believe the award winners can fill the niche for just about any need and budget, but if you find another seat in the group that looks more worthy for you, compare it to the top-scoring or award-winning products in this review. The variety of options might seem overwhelming. Still, we have your back with information and a detailed analysis of many of the viable candidates, so your decision can be as easy as 1,2,3.

Optional Reading: Car Seat Lingo

To help you understand all things car seats, we have provided a little terminology insight that you might come in contact with when reviewing car seat information. Knowing the lingo can help you stay the course and ensure that you understand the details of what you are reading. This knowledge is important for interpreting information easily.

The terms and definitions are from the National Child Passenger Safety (CPS) Certification Training Program manual. While some definitions have been slightly changed to increase readability, the intent/meaning is the same. You can read these definitions here.

Honest, objective reviews. Led by a Pediatrician.

BabyGearLab was founded by a Pediatrician Mom with a mission to provide a reliable, independent, source of information to new parents. Our experts have tested thousands of baby and kids products to share key performance, health, and safety findings. We spend tens of thousands of dollars crash testing car seats to inform our ratings. And, we combine our review work with gobs of expert parenting advice. To assure complete independence, we buy all the products we test ourselves. No sponsored content. No ads. Just real, honest, side-by-side testing by people who care.

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