Why your child's weight and height percentiles matter
Posted by Margaret Bolt on
IT’S ALL ABOUT YOUR CHILD’S PROPORTIONS!
![](https://cdn.shopify.com/s/files/1/0268/7723/1289/files/Axkid-One-2_480x480.png?v=1720791417)
Under the older R44 regulation, the highest weight that extended rear facing car seats go up to is 25kg. All new car seats now meet the R129 regulation and under this reg the highest limit is 36kg. But the higher weight limit doesn’t mean that these seats will always last longer than R44 seats like the Axkid Minikid 2, or than R129 ISOfix seats up to 125cm with lower weight limits. It’s all about the child’s proportions.
The R129 height limit for ERF car seats is 125cm. They are not allowed to keep using the seats past 125cm even if they still fit.
Children are all different, some are tall and slim, others short and heavy, some have longer legs, others have a longer torso.
I don’t want any children to grow out of their car seat by weight before height, they should all be able to rear face until they’re 125cm.
An average child who is on the 50th percentile for both height and weight will be 125cm when they are seven and a half years old, by which time they will weigh 24kg.
These are a few examples of children whose weight and height proportions vary and how that should be taken into account when choosing a car seat:
A child who is 50th for height and 25th for weight, will be 125cm and weigh 22kg when they’re seven and a half. They will be fine in seats that have lower weight limits such as the Axkid One 2, because they won’t outgrow the seat by weight before they’re 125cm. A seat with a higher limit such as a Minikid 4 won’t last them any longer despite the weight limit being 13kg higher.
A child who is 25th for height and 75th for weight will reach 125cm when they’re just over eight, and weigh 28kg. A seat up to 25kg would have lasted them until they were seven, and one up to 23kg only up to just over six. For those children a seat with a 36kg will be best.
It’s also not always true that a child on the 90th percentile for both height and weight will last longer in a Minikid 4 than a Minikid 2. They won’t fit in any seat for as long as a child on the 9th percentiles, but the Minikid 4 won’t necessarily last longer just because it has a higher weight limit.
The reason for that is the difference in torso height. Two children can be exactly the same height when they’re standing side by side, but very different when they sit down. This is because some people have a long torso and others have longer legs.
The opposite is also true. A child with a short torso and long legs will reach the 125cm height limit when they still fit in their R129 seat, but have to stop using it because 125cm is the regulation limit. These children can use the Minikid 2 or Move for longer because these seats only have a weight limit, but no set height limit so they can use them until they no longer fit.
(We don’t have a date yet, but at some point the last two remaining R44 ERF seats, the Axkid Minikid 2 and Move, will disappear.)
So to sum up… When choosing your extended rear facing car seat, look at your child’s height percentile and predict how old they will be when they reach 125cm. Then look at how much they are predicted to weigh at that age based on their current weight percentile. If they are likely to weigh less than 22/23kg when they’re 125cm you can choose any seat you like, but if they’re heavy for their height they will need a seat up to 36kg.
I know it can be confusing, but I hope that I have made it a bit clearer for you.
https://www.rearfacingtoddlers.com/collections/child