Whether you are a parent expecting their first child or someone who has some previous experience of buying child car seats, it is very easy to become overwhelmed by the massive amount of information available on this subject, and the long list of safety and convenience issues that you have to consider when choosing the perfect seat for your child and your family’s particular circumstances.
Buying the right car seat for your child is a big responsibility and nobody wants to make the wrong decision. It is perfectly normal to get stressed about this decision and I can understand why many parents and other caregivers find themselves completely overwhelmed by the prospect of having to make a decision as your baby’s birth draws near or the date for transitioning from an infant car seat approaches.
In my best convertible car seat buying guide I hope to alleviate some of your fears and anxieties, to dispel some of the myths and misunderstandings that surround convertible car seats, and ultimately to help you to make a better informed purchasing choice for you and your child.
If you are looking for something specific, you can take a short cut to the relevant part of this post by clicking on the links:
- What is a Convertible Car Seat?
- Convertible Car Seat Features
- Convertible Car Seat Ratings
- Best Convertible Car Seats for Specific Circumstances
- Leave a Comment
What is a Convertible Car Seat?
If you already know what a convertible car seat is please don’t be insulted by my addressing this basic question, but I want to make sure that this buying guide is suitable for everyone to use, including those who know absolutely nothing about child car seats.
There are 2 different types of car seat that are suitable for use from birth.
1. Infant Car Seats from Birth
Infant car seats are specifically designed to be used by newborn babies and will usually remain usable for about 1 year before they have to be replaced by a convertible car seat. Each infant seat will have a different maximum height and weight limit and, therefore, a different usable length of time, but most don’t go beyond about 35 lbs i weight or 32 inches in height.
So, whether or not you choose to buy a convertible car seat for use from birth, you will almost certainly have to buy one further down the line when your child outgrows their infant seat.
The other notable features of most infant car seats are they:
- They are always used in the rear-facing position
- They come with carry handles
- They can often be used as part of a stroller travel system
- They often come with a base that remains in the car and into which the seat is installed
Here is an example of an infant car seat.
2. Convertible Car Seats from Birth
Most, but not all, convertible car seats can be used from birth and can continue to be used until your child is aged somewhere in the region of 7 years old, depending obviously upon where they fall on the size spectrum.
There are many different models of convertible car seat and they each come with their own specific child height and weight limits. If your child has, or is likely to have, a body shape that is at one of the extremes (i.e., very heavy, very tall, very light, very small) then it is even more important that you pay particular attention to the seat’s minimum and maximum height and weight limits before you buy it. I have provided further guidance in relation to which convertible car seats are more suitable for certain categories of child further down the page.
One of the main advantages of a convertible car seat over an infant car seat is that it too can be used from birth and, importantly, it removes the need for you to spend an additional $200 or so on an infant seat before later transitioning to a convertible seat.
So convertible car seats are a much more cost effective way to go, but there are obviously other factors to consider, including safety issues and whether or not you want to be able to carry your baby around in their car seat.
For some people, the desire to use an infant car seat as part of a stroller travel system is so powerful that they don’t want to even consider convertible car seats.
Convertible car seats cannot be used as part of a stroller travel system. They are designed to remain installed in your vehicle even when they are not in use. They are heavier than infant seats and do not come with carrying handles as they are simply not designed to be carried around with a child inside them.
Some convertible car seats can actually be used beyond the normal age / weight/ height limits of this category of seat. The Diono Radian RXT is one of those seats that has stood the test of time and can be used all the way from birth to 120 lbs! So, the Radian RXT could be the only car seat that you ever needed to buy.
Most convertible car seats, however, will last only until either your child weighs more than 60 or 65 lbs or their height exceeds about 49 inches.
Convertible Car Seat Features
So, what should you look out for when looking for the best convertible car seat?
What are the most important features that you can expect to find on the best convertible car seats?
1. Convertible Car Seat Installation Methods
There are broadly 2 different methods of convertible car seat installation and the best convertible car seats will allow you to use both.
Firstly, you can install a convertible car seat using what are called LATCH connectors, provided that your vehicle has LATCH anchor points fitted (which most modern vehicles do).
LATCH stands for Lower Anchors and Tethers for Children and is a method of connecting a child car seat to the metal structure of a vehicle to ensure stability. There are rigid LATCH connectors and flexible LATCH connectors, but they both perform the same essential function of achieving a firm connection between car seat and vehicle.
Flexible LATCH (as shown above) requires you to position the connector to the metal hook and then tighten the LATCH strap. Rigid LATCH connectors do not use straps and you generally just have to push them on and pull them off with the assistance of a push button. Rigid LATCH is more common in Europe (and considered to be easier to use), but there are some US convertible seats that come with Rigid LATCH.
LATCH is popular amongst parents and car seat safety technicians because it is generally mush easier for people to install a convertible car seats securely when using LATCH connectors than when trying to install using the vehicle’s adult seat belt.
Theoretically, LATCH installation is no safer that belt installation but in the real world, it is probably safer because you are much less likely to mess up the installation process when using LATCH connectors.
Some very worrying research has concluded that as many as 75% of car seats are incorrectly installed in vehicles. An incorrectly installed car seat is an unsafe car seat and creates a serious risk of injury to your child in the event of a collision. So, don’t skip this part of the User Manual, even if it appears complicated. It is probably the most important thing to get right and, for those who prefer visual aids to learning there are plenty of helpful guides on YouTube from experts demonstrating how to install most of the best convertible car seats properly.
Even if your convertible car seat comes fitted with LATCH connectors, you must bear in mind that this method of installation cannot be used for the entire life of the seat. Because vehicle LATCH connectors are only rated as begin capable of handling a certain load, each convertible car seat will come with a maximum child weight limit for LATCH use. Once your child’s weight has exceeded this LATCH weight limit, you must re-install the seat using the vehicle’s seat belt instead. The seat’s User Manual will tell you what its LATCH limits are.
Even if you don’t start out by installing your child’s convertible car seat using the seatbelt method, you probably will have to at some stage due to the LATCH weight limits that I have already mentioned.
Again, some seats come with much easier belt installation mechanisms that others.
Everyone is capable of learning how to install a convertible car seat using the vehicle’s seatbelt, but it might take you a little time and effort to get it right if you have no previous experience. It is vitally important to read the User Manual carefully rather than simply trying to figure it out on your own.
It is impossible to provide a meaningful description of how to install a convertible car seat safely within a vehicle using the vehicle’s seatbelt due to the wide variety of methods used by different seats.
Some seats come with features such as built-in lockoffs to make it easier to secure the seat using the seatbelt. These lockoffs basically serve to clamp the seatbelt so that it cannot loosen. Some, like the Britax ClickTight convertible car seats come with an simpler (almost foolproof) mechanism for ensuring a secure installation.
Whichever installation method you use, just remember to use the “1 inch test” after you have done so. The “1 inch test” requires you to pull the seat forwards and backwards. Provided the seat does not move by more than 1 inch when you do so, it is installed securely.
2. Convertible Car Seat Height & Weight Limits
It goes without saying that convertible car seats should only ever be used by your child if their weight and height falls within the seat’s weight and height limits.
There are always minimum and maximum limits to consider, and some seats also recommend that they can only be used in certain modes when your child has reached a certain age.
I will deal with the issue of extended rear-facing car seats and their limits later on, but for now I want to concentrate on the issue of a seats overall limits.
In terms of minimum weight limits, the standard convertible car seat usually designed for use form 5 lbs and upwards. This will be more than adequate for most babies since the average birth weight of a baby in the US is about 7.5 lbs.
If you baby is below that weight, or is likely to be below that weight when born (perhaps because you are expecting multiples or there are some other health issues), you will need to look either at an infant seat or one of the convertible car seats that is rated as suitable from 4 lbs.
Many of the best convertible car seats will also come with some form of infant insert, which is designed to provide extra support around the head and neck areas and also acts to boost a baby’s body up so that a safe and snug fit can be achieved. The Maxi-Cosi Pria 70 with TinyFit, for example, is only suitable for use with a newborn baby (as light as 4 lbs) if you use the infant insert. Without the insert, you would not be able to carry your child in it until they had reached the minimum weight limit of 9 lbs.
A convertible seat will also come with overall maximum height and weight limits. Weight limits are commonly about 65 lbs and height limits commonly about 49 inches.
Bear in mind that children often outgrow their car seats by height long before they reach the maximum weight limit. So, when comparing car seats don’t just concentrate on the weight limits and forget to factor in the height limits too. This is especially important if your child is likely to be tall and slim because, perhaps one of their parents is an Olympic basketball player!?
3. Extended Rear-Facing Convertible Car Seats
Extended rear-facing convertible car seats are those that have higher maximum weight and height limits for use in the rear-facing position than is normally the case.
It is quite common for seats to have rear-facing weight limits of 40 lbs and height limits of about 43 to 44 inches.
It is further complicated by the fact that some manufacturers refer to standing height limits and others use seated height limits, and also the fact that rear-facing height limits are often set by reference to how far your child’s head is from the top of the seat.
There are, however, some convertible car seats on the market that promote and facilitate extended rear-facing. The Clek Foonf and the Graco Extend2Fit seats, for example, both have rear-facing maximum weigh limits of 50 lbs.
Why is extended rear-facing so important?
All convertible car seats will start off being installed in the rear-facing position because that is how they are designed to be used so as to provide the best possible protection for your baby. But, there will come a time when you will be tempted to turn them around to forwards-facing, either because they start complaining or simply because you thing that it is the next developmental stage.
Convertible seats will commonly be rated for use in the forwards-facing position from as little as 20-22 lbs and upwards, provided that your child is at least 1 year old. Many parents mistakenly think that they are supposed to switch their babies around at that stage just because the User Manual says that it is permitted.
This is a common mistake and a practice that flies in the face of some clear and compelling scientific evidence that has proved beyond any serious doubt that rear-facing is much safer than forwards-facing. Rear-facing is not just a little bit safer. It is now considered by experts to be as much as 5 times safer than forwards-facing!
Now, i’m not going to describe the research studies in great details here, but it is notable that the American Academy of Pediatrics has considered this evidence and now advises that children should remain rear-facing for at least 2 years and preferably longer.
In countries such as Sweden, where their death and serious injury rates are far lower than other countries, children routinely remain rear-facing for 4 years and there are seats on the US market that will allow your child to do the same. I highly recommend this practice.
4. Convertible Car Seat Top Tether Straps
The best convertible car seats come with top tether straps. These are straps that connect the top of the seat to a fixed anchor point on the vehicle itself. The purpose of the tether strap is to provide extra stability to the top of the seat and prevent it from moving forwards in a collision. By restricting the forwards movement of your child’s head, the top tether is an essential part of reducing the risk of serious injury to your child.
They must always be used when your child’s convertible car seats is being used in the forwards-facing mode.
Generally, they cannot be safely tethered whilst being used in the rear-facing mode.
The Britax ClickTight range of seats used to allow top tethering in the rear-facing position, but not any more. You might find some older videos on YouTube that still claim that you can tether these seats whilst facing forwards, but this is currently not correct. If you own one of these seats, just make sure that you double-check the instructions that come with your version before tethering in this manner.
The Diono Radian RXT us one seat that uses a top tether strap whilst being used in both forwards and rear facing modes.
5. Side Impact Protection on Convertible Car Seats
Side impact collision account for some of the most serious injuries to children in road traffic collisions. It stands to reason that if a car is struck forcibly to the side the damage and resulting injuries are likely to be much more serious that a frontal collision, and the research data backs it up too.
Given that fact, it is truly remarkable that there is no mandatory Federal test for side impact protection of convertible car seats in the US. There are crash tests that every convertible car seat must pass before it is allowed to be sold in the US, but there are no side impact collision tests to pass.
Convertible car seat manufacturers make some very impressive claims about their particular side impact protection systems, but you cannot judge those claims by reference to any published test data when trying to make an informed decision. The manufacturers themselves will have performed side impact testing on their convertible car seats, but they generally don’t publish that data for you to read. Instead, you are left to use your common sense and trust that the manufacturer is painting a fair picture of their side impact protection systems.
One thing to be aware of is that extra side impact protection often means a wider car seat, as you can see if you compare the Britax Marathon ClickTight (1 layer of protection) with the Britax Advocate ClickTight (3 layers of protection). The Marathon is just 18.5 inches wide, whereas the Advocate version is 20.5 inches wide. This might not sound like very much, but it can make all the difference if you have a small vehicle or you need to fit 3 in a row.
The National Highway Traffic Safety Administration (NHTSA) has lobbied for the introduction of official side impact tests for convertible car seats, but there is as yet no sign of any positive Government action on this important issue. Even if a Bill were to be passed today, the proposal is that there should be a 3-year period of adjustment prior to car seat manufacturers having to comply with any new side impact safety standards. So, don’t expect any changes to this testing regime any time soon.
6. Convertible Car Seat Harnesses & Headrests
Convertible car seats restrain your child using a 5-point harness. They are also fitted with headrests to provide extra protection in the event of side impact collisions and to also provide support to a child and prevent their bodies from flopping over to the side when, for example, they fall asleep on long journeys.
I am not going to provide instructions here on how to correctly use a 5-point car seat harness and the chest clips that come with them, as you will need to consult the instruction manual and its better to learn by watching video demonstrations by experts, such as “The Car Seat Lady”.
Since all convertible car seats come with a 5-point harness, you can’t use this feature as a reason to choose one over another. They will vary in how many possible harness positions there are and you will want to ensure that you buy a seat with a good number so that you can ensure a proper fit at all stages of your child’s development.
Their 5-point harness adjustment systems on convertible car seats are, however, often very different. Obviously, as your child grows you will need to adjust the shoulder harness straps.
The standard shoulder harness strap can only be adjusted by removing the entire seat from your vehicle, unthreading the harness itself (not always easy if you have adult hands), making the necessary adjustment, and then rethreading the harness prior to reinstalling the seat in your vehicle. You will need to do this multiple times during the life of the seat and it can become a real pain.
Some of the best convertible car seats, however, come fitted with what are called “no rethread” harnesses and they often automatically adjust to the correct position by simply adjusting the seat’s headrest. Using one of these systems makes what would otherwise be a laborious process into a quick and simple one.
The Britax Boulevard ClickTight seat comes with a 14-position adjustable headrest that also serves to adjust the shoulder harness straps at the same time. You simply squeeze the headrest adjustment handle at the top of the seat and pull it upwards into the correct position.
7. Convertible Car Seat Recline Positions
The best convertible car seats will have multiple recline positions for you to utilise in order to get the seat properly positioned in your vehicle. These seats are manufactured for use in vehicles of all shapes and sizes and the more recline options that a seat has the wider the range of vehicles that it is likely to fit in.
They will also have a recline level indicator to provide you with clear instructions about which recline angles are suitable for different modes of use and some visual confirmation that you have got it right.
Again, each seat is slightly different in terms of the number of recline positions and the instruction provided in relation to which recline angles are suitable for specific situations. Generally, babies in the rear-facing position should be inclined by at least 45 degrees to ensure that their heads do not loll forwards and restrict their breathing.
8. Convertible Car Seats with Steel Frames / Anti-rebound Bars
Some premium convertible car seats are manufactured with integrated steel frames to provide extra rigidity.
You can also find convertible car seats with anti-rebound bars, which comprise a padded steel bar that is attached to the foot-end of the seat, and which is designed to reduce the amount of rebound during a collision.
If your vehicle were to drive into collision with the rear of a vehicle in front, for example, the initial forces involved would compress the seat into the back of one of the front seats. The secondary reaction, however, would cause the seat to rebound back towards the rear of the vehicle and, without an anti-rebound bar, there is a risk that your child’s head would come into contact with the vehicle’s seat.
The Clek Foonf has both an integrated steel frame and an anti-rebound bar and these top-end safety features go some way to explaining its hefty price tag.
9. The Size & Weight of a Convertible Car Seat
Unless you need to frequently move a convertible car seat from one vehicle to another, its weight is probably going to be one of the least important factors to consider. As I have already pointed out, these seats are not designed to be carried about and so their weight is of limited relevance to any purchasing decision.
The physical size of a convertible car seat, however, may well be very relevant to your final choice.
There are 3 relevant dimensions to consider; height, depth, and width.
There is not much point in me stating the obvious when it comes to car seat dimensions and how they ought to be taken into account. Obviously, if you need to fit 3 seats in a row in a standard sized vehicle, you will be looking for narrow seats. If you have exceptionally long legs and the car seat will be positioned behind the back of your seat, you will need to look for a seat that has a combination of good recline options and smallish height and depth dimensions.
Convertible Car Seat Ratings
Every convertible car seat that is sold in the US today has been rigorously tested and found to meet or exceed all relevant Federal Safety Tests. All convertible car seats on the market, therefore, are considered to be “safe”.
There are some limitations to the extent of these tests as I have already mentioned above when discussing side impact protection systems.
If you are planning to spend hours on the internet trying to hunt down some sort of league table the ranks all convertible car seats in order of safety, you are going to be sadly disappointed. There are no universally accepted league tables and no manufacturer can legitimately claim that their seat is “the” safest.
The Federal Tests are simply pass or fail. There are no grades handed out for you to compare.
That said, there are some official ratings for you to consider if you wish and they come from the NHTSA.
The NHTSA “Ease of Use” Ratings
Although the National Highway Traffic Safety Administration (NHTSA) does NOT carry out the sort of crash tests that could be used to rank all convertible car seats in order of safety, it does carry out some very detailed “Ease of Use” evaluations on these seats and helpfully publishes their findings.
As the NHTSA makes it clear on its own website, these “Ease of Use” tests are NOT full safety tests and they should not be mis-used in this way.
They are, however, a useful starting point when considering which is the best convertible car seat for your child
So, what exactly are the NHTSA “Ease of Use” Ratings?
In short, they are a measure of how easy a seat is to use … the clue is in the title!
According to the NHTSA, the safest convertible car seat is the one that:
- is appropriate for your child’s age, height and weight
- fits in your vehicle correctly; and
- is easy to use
The NHTSA looks at the following factors:
- The Content & Clarity of the Seat’s Instruction Booklet
- How Easy it is to Install the Seat
- The Content & Clarity of the Seat’s Labels
- How Easy it is to Restrain the child in the Seat
Each of the 4 “ease of use” factors listed above are given a “star rating” out of 5 and then an overall star rating at the end that takes account the combined effect of these individual factors.
I mentioned previously that some premium convertible car seats come with clever and foolproof belt-installation technology and, since the safest seat is usually the one that is installed properly, it is hardly surprising that the only series of convertible car seats that can currently boast a 5-Star Overall Ease of Use Rating are the Britax ClickTight Convertible Car Seats.
Best Convertible Car Seats for Specific Circumstances
There are some specific circumstances that commonly require a more focussed and specialised approach to finding the best convertible car seat for your child.
Here are some of the most common sets of special circumstances that parents can be faced with.
1. Best Convertible Car Seats for Small Babies
Some convertible car seats, like the Clek Foonf, are unsuitable for use with underweight babies.
The best convertible car seats for small babies are those that have a low minimum weight limit, an infant insert, and shoulder / crotch harness positions that facilitate a good snug fit despite the baby’s very small size.
2. Best Convertible Car Seats for Tall Kids
At the other end of the size spectrum come those kids who are likely to grow to an above average height.
You will probably want to look for an extended rear-facing seat and one that also has a high overall height limit.
The Diono Radian RXT and Diono Rainier would be a good place to start your search and I have previously written an in-depth comparison review of these seats.
3. Best Convertible Car Seats for Extended Rear-Facing
Whilst some parents are perfectly happy with a convertible car seat that can be used in the rear-facing position for 3 years or so and, in you are one of those people, then you have a wide range of options to choose from.
If, on the other hand, you want to keep your child rear-facing for as long as possible, you will need to look for an extended rear-facing convertible car seat.
4. Best Convertible Car Seats for Small Cars
Not everyone drives around in a massive SUV with 3 rows and plenty of space.
If you have a small car, you will have to take care to ensure that you choose a seat that is not too large to be installed properly within your vehicle.
There are 3 convertible car seats that immediately spring to mind as being well suited for installation in small vehicles and I have previously published detailed reviews of all of them:
5. Best Narrow Convertible Car Seats
Perhaps you have a narrow vehicle or have 3 children that need to sit alongside each other, or both?
If so, you will need to find the best narrow convertible car seats.
Most convertible car seats simply won’t fit comfortably 3 in a row within a standard sized vehicle, but there are a couple of excellent options that will be suitable.
Get in Touch
I hope that you now have a better understanding of the sorts of things that you need to consider before buying a convertible car seat for your child.
If you have any thoughts on any issue raised, or want to offer an opinion of which is the best convertible car seat for particular circumstances, please leave a comment in the box below.