Which car seat do you need by age? | Safe transport from day 1

A good car seat is one of the most important purchases for new parents. It is not only required by law, but also vital: a correctly chosen and correctly installed car seat can prevent serious injury in an accident. But with so many options and rules, it can feel overwhelming: which car seat is right for your child, and at what age should you switch?

In this blog, we clearly explain which car seat you need by age and weight, and what you should definitely pay attention to when making your choice.

Car seats are divided into different groups

Car seats are divided into four main groups: 0/0+, 1, 2 and 3.

In addition to these separate groups, there are also combined car seats. You often come across names such as Group 1/2/3 or Group 2/3. This simply means that one car seat is suitable for multiple groups and can therefore be used for a longer period of time.

A car seat from Group 1, for example, is suitable for children weighing around 9 to 18 kg. A Group 1/2/3-car seat, on the other hand, grows with your child and can be used from around 9 kg to 36 kg, which corresponds to an age of about 1 to 12 years. Thanks to these combined groups, you won't need to buy a new car seat as quickly and can enjoy a longer period of use.

Group 0+ (0 to 13 kg)

A group 0+ car seat, also known as a baby car seat, is suitable from birth. You can often recognise them by the 'shell' design with a handle, which makes it easy to lift the seat out of the car.

• Placement: always rear-facing – this is the safest for your baby's neck.

• Attachment: with seat belt or ISOFIX base

• Tip: only switch when the head sticks out above the edge or the weight limit has been reached (usually 13 kg)

💡 Brands such as Cybex and Thule offer excellent 0+ models.

Group 1  (9 to 18 kg // ±12 months to ±4 years)

If your baby becomes too big or too heavy for group 0+, you move on to a group 1 car seat. This is roomier and offers more support for older babies and toddlers.

• Placement: forward-facing or rear-facing (rear-facing is mandatory until 15 months. It is even recommended to keep doing this longer if possible)

• Attachment: with seat belt or ISOFIX

• Extra safety: built-in 5-point harness and side protection

💡 Consider models with a swivel function for easier getting in and out.

Group 2/3 (15 to 36 kg // ±3.5 years to ±12 years)

These car seats are intended for older children who no longer need an internal harness. They use the vehicle's regular seat belt.

• Attachment: with the seat belt, sometimes supplemented with ISOFIX for stability

• Adjustable: height-adjustable backrest, headrest and often seat base

• Important: your child must be at least 135 cm before using a booster seat can be fully omitted (mandatory in Belgium up to 135 cm)

💡 Make sure the shoulder belt runs properly across the chest, not over the neck or stomach.

i-Size: the new standard

Alongside the classic 'group classification', there has been the i-Size system for several years, which classifies car seats based on height and age, not weight. i-Size seats are often safer because they:

• Are tested more strictly for side impact

• Require ISOFIX for better installation

• Require rear-facing transport up to at least 15 months

i-Size is the future and is gradually becoming the norm in Europe.

Summary overview

* Please note: the recommended weight and recommended age of a car seat "group" may vary slightly from brand to brand.