Choosing the right car seat for your child

Choosing the right car seat for your child

What is the best car seat for my child?

The best car seat is one that fits your child, fits your car(s) and is easy to install and to use. Here are some useful tips and recommendations to help you decide. 

Don't know which car seat is right for you?

Check out the Maxi-Cosi Car Seat Advisory Tool

Height and weight more important than age
There are two different regulations in car seats: i-Size (or UN R129) and ECE R44/04 car seats. i-Size uses the length of children to classify car seats, ECE R44/04 uses weight to divide car seats into groups.

i-Size (UN R129) regulation

i-Size, or also known as UN R129, is a new EU safety standard and increases the safety level for children in cars. It provides extra protection in several ways, most notably by providing rearward facing travel for children up to 15 months.

i-Size uses the child’s length to determine the fit in a car seat rather than weight or age. Parents seem to know the length of their children better than their weight and there is a lot of variation between the length of children and their age/weight. Length tells best if a child fits a seat well and when a parent should switch to the next car seat.

i-Size car seats therefore are always designed to be used for a range of height (for example from 67 cm tall to 105 cm).

ECE R44/04 regulation

ECE R44/04 child car seats are divided into groups, based on the weight of the child (see summary).

Car seat




Group 0+

birth to 13 kg

up to 12 months


Group 1

9 to 18 kg

9 months to 3½ years


Group 2/3

15 to 36 kg

3½ years to 12 years


Never buy a child car seat that is too big, make sure it is appropriate for your child’s height (i-Size) or weight (ECE R44/04 ) from the first day of use. The appropriate category is stated on the orange ECE approval often placed at the bottom of the car seat. Age categories are also often stated, but because one child can be heavier than the other, the age group should be considered primarily an indication.

It is safest to buy a car seat to suit your child’s height or weight as they grow, rather than buy a car seat that covers the whole weight range (using the same car seat from birth to 3½ years, or longer).

The Car Safety Expert says: “It's not just the age of your child that you have to consider when choosing a child car seat. You also have to consider their height (for i-Size car seats) and weight (for ECER44/04 car seats) and which seat provides the most secure fit in your car; whether your baby or child will be taking long or short journeys and if you will need to transfer your child car seat from one car to another, as well as what’s most convenient for you as a parent. My top tip would be opt for a seat that fits onto a base. Once it’s in securely, you’re guaranteed peace of mind your little one is safe, and the seat simply clicks in and out with ease, perfect for busy parents."

When is it time to switch to the next stage car seat?

Maxi-Cosi advises to wait as long as possible to switch from a baby to a toddler car seat. Babies are best protected travelling in a rear-facing direction. This way, the energy of the impact is absorbed and distributed by the seat shell and car seat belts.

Switch from baby to toddler seat
Your baby has outgrown their baby car seat when the top of their head reaches the top of the car seat. Do not switch to the next stage car seat until this time.

Switch from toddler to child seat
A toddler only needs to switch to a group 2/3 car seat when the shoulder straps of the harness are lower (approx 2cm) then your child's shoulder position. 

No more car seats
You no longer legally require a child car seat if your child is 1.35 or 1.50 meters tall (approx. 12 years of age). See list of countries below for exact maximum height. Children no longer using car seats must use the regular car seat belts at all times.

How to install an ISOFIX car seat

Read more about how to install an ISOFIX car seat.


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