Why are car seats all based on height rather than weight now?

[BlueberryMacaron]

I’m looking for a next stage car seat for my baby in the Black Friday sales, but I’m confused about why they’re all height limits instead of weight limits. He is off the top of the height charts, but only between 50 and 75th centile for weight, and the length is all in his legs. It doesn’t make sense to me that he could technically outgrow a seat just because his legs are long, if he actually fits fine in the seat, the straps fit over his body, and he’s well within the weight limit. When I’ve seen posts about ERF people always say that legs don’t matter and children can just bend them. Are there any seats with a harness limit above 125cm? He’s 8 months and I’m hoping he slows down but I don’t think he’s going to

I have an Axkid Minikid 4 that my 5.5 year old on the 91st-98th height percentile is still comfortably rear facing in and has quite a bit of room left in.

If you are looking for a long lasting seat for a tall child the Minikid 4 has the tallest shell on the market at present. It has the same height limit as many other ERF seats (125cm) but my son already doesn’t fit in many of those despite being under the height limit.

I think this seat will genuinely last him until he reaches the height limit and outgrows it. He will be about 6.5 by then.

Because it is the seat belt geometry that is important? More important then weight, anyway

This is for harnessed seats not seatbelt fitted seats. Obviously if they don’t fit under the straps they can’t use the seat any more, but different people carry their height differently. A child like mine with long legs and short torso could fit happily in a seat like the Axkid one the pp mentioned, but have to stop using it because they’ve reached a certain height. I get a weight limit because the buckle is only so strong. I get not using a seat when the straps can’t go over their shoulders because then they’re not restrained. But 125cm just feels arbitrary.

This is probably a stupid point, but a child could be 125cm so need to stop using their seat, but if they lost both legs at the knee they could use the seat again even though nothing relevant to how the seat fits has changed. Does that make sense?

I get what you’re saying OP but even boys on the 99th centile will get to at least age 5 in the Axkid Minikid 4. Your little one is only 8 months old so there’s a possibility they may change shape and proportions or even centiles by the time they are getting old enough that outgrowing their ERF seat is imminent.

Also just in the 5 years since my eldest has been born there is now so much more choice of ERF seats and the technology has moved on loads. So I would imagine that it is a strong possibility that there will be even more innovation in the next 5 or so years.

If your son is on the 91st percentile for height he will likely get to about age 6.5/maybe closer to age 7 with the seats that are available at present. By which time he will likely be very ready for a high back booster.

The reason it was changed to height rather than weight is for two reasons - the first one is that children vary much more in weight than they do in height by age (apparently) and realistically the graduation through car seat stages should happen by age, height/weight has only ever been a proxy for this and in order that the car seats are designed to contain a child of that specified size for crash testing purposes.

The second reason is that in most of Europe, children's clothing is sold in height bands rather than age so most parents have a rough idea of how tall their child is all the time even without measuring them. You know if they are wearing size 98 clothes, they will fit fine into a seat up to 105cm. So it's thought to be easier to understand. It also is easier for car seat shops to provide a height chart than a set of scales.

You're right that practically, the important part in terms of safety of fit is the size of their body from bum to shoulder. And TBH for most seats on the market for this reason it's not likely to matter that much if they are e.g. 107cm in a 105cm limit seat. There are exceptions, but generally the height limit is a bit less strict than a weight limit was.

The height limits of 75cm / 87cm / 105cm / 125cm are based on the old weight categories which were 10kg / 13kg / 18kg / 25kg and roughly correspond to 9 months / 18 months / 4 years / 7 years. Obviously if your child is taller or heavier than average, they might not fit into these categories.

However if you're talking about a baby, I don't think you need to worry overly about a 125cm height limit - are you mixing this up with 105cm? 125cm on the 91st centile is 6.5 years, which is unlikely to be a problem.

105cm on the 91st centile is about 3.5, which is not great but a lot of people have another baby by that age so they swap the first child into a 125cm seat and use the 105cm seat for the younger sibling.

Maybe I’m missing something but why would you need a harness over 125cm? Even a very tall child isn’t going to reach that height until over 6 years old and they will be totally fine to move into high backed booster at that age. Are you confusing with the 105cm limit perhaps? That is awkward because a taller child will be 105 at 3 but it’s better to wait until 4 to put them into a booster if for no other reason than you often can’t trust them to sit sensibly. But if you want an extended rear facing seat then you can easily get around that by buying a 125cm limit one.

I think I did get confused with 105cm car seats 🤦‍♀️ I guess months of no sleep takes its toll. Thanks everyone, hopefully he'll slow down but definitely going to get a 125cm car seat for him.

I spent a lot of time on Google and ChatGPT and still a bit confused. There are two Axkid Minikids but I think both need to have tethering? I've watched installation videos and they make it look easy but it seems like it would be hard for me.And the Axkid One+ 3 is Isofix and 125cm but so expensive. It might be worth it if it lasts as long as the Minikid but if the Miinkid is the tallest carseat then probably not and maybe best to suck it up and learn. I'm dyspraxic though so things like that intimidate me. I couldn't tie my shoes until I was 10 and plugging a seat in feels so much safer even though everyone says online its the same. I've never even used a seatbelt with the Cybex, I just move the base between cars because I see that as easier than the seatbelt.

Then I saw on Google this page about the Axkid Core which doesn't need tethering which sounds better, but because it's new I don't know if the carseat is as big as the Axkid Minikid. And it's still seatbelt which is more of a faff than isofix and it doesn't say how much it will cost, so might not even be a saving. I might practise using a seatbelt with the my Cybex and see how that goes, but I feel nervous thinking about it.

Promise tethers are not that hard! Have a look at this video for how to install.

Or go on Axkids website and search for your nearest stockist, a car seat specialist will be able to install it for you. Our local one is brilliant.

The Axkid Minikid 4 Max has the auto tightening tethers which makes it even easier.

The Axkid seats are excellent, we have five of them!

I agree that a tethered seat can seem a little daunting at first, but if you search for your nearest independent retailer they will be able to help you fit the seat in your car and continue to provide you ongoing support as you need it. The other thing to remember is that unless you’re moving the seat regularly between vehicles, you don't need to install the tethers every time you use the seat, although it’s a good idea to check them regularly to make sure they remain tight and secure, along with the seat belt.

Axkid have the Minikid 4 Pro and Max. Is definitely go with Max for the autotightning tethers. They have the tallest shell on the market, so are good for children how carry their height in their torso. Axkid also have the One 3, which is an isofix seat. I think that has quite a lot of legroom for the child, but a lower weight limit as it’s isofix. It’s also much more expensive. I’ve heard about the new Axkid Core but I’ve not idea about the price point. The BeSafe Stretch can be fitted with more leg room, although that may come at a cost to the front seat leg room, especially if you have a car with a small cabin. I’d avoid the Britax ERF seats as although they have the same height/weight limit, they are often outgrown before 125cm and don’t have as much leg room.

In your shoes I’d definitely check out your local independent retailer and get their help and support in selecting the right seat for you and your child.

I remember having an argument in Halfords that my dc was too light for the next seat up and I had to prove she was too tall for the 5 point harness (head way out the top). She’s always been underweight and tall. She’s now 17, 5’9” and a women’s size 6 so she’s stayed on that trajectory.

We have an Axkid One. It goes up to 125cm/23kg/7 years and it's isofix. My MIL moves it from ours to her car easily. Yes it is expensive and it is a little bulky (we had to get a bigger car when our lease was up) but it's brilliant. My little boy is so comfortable in it and the insert removes when he's 105cm. If you have a car seat specialist that can travel to you I recommend trying it out!