Child car seats: how to buy and fit the safest seat

What to look for in a child car seat, how to ensure it's fitted correctly and how the latest advances in testing are improving safety...

Child car seats: how to buy and fit the safest seat

Keeping children safe in our cars is a responsibility every parent takes seriously, but finding the right child seat is more complicated than you might realise. Do you choose a seat secured by the car’s seatbelt, or with Isofix mountings? Just what is Isofix, anyway? And which type of seat will suit your child best, forward facing or rear facing?

When you’ve decided the type of seat to buy, you’ll find there’s a huge choice of models and wide range of different retailers. Not every seat will suit every car, and not every shop assistant will have the expertise to help you choose the most suitable seat for your child and your vehicle.

Even once you’ve found the right seat, and bought it from a shop that’s given you a thorough demonstration of how it works, the seat won’t protect your child unless you fit it properly. That means securing it correctly in your car, 
and adjusting the harness precisely.

Complicated? Yes. Worth the effort? Definitely. So here’s our essential guide to choosing the right seat for your child.

Watch our video on fitting a Cybex Sirona Z child car seat

What kind of child seat is safest for my child?

One that’s appropriate for your child’s weight or height. There are two different standards that child seats can comply with: R44 and R129 and i-Size. Read our guide to i-Size seats here.

R44 seats are categorised in a group system so you can quickly decide if it’s worth putting a particular seat on your shortlist. Group 0 seats are for the youngest babies weighing up to 10kg and Group 3 seats for children weighing 22-36kg. Many seats cover more than one group, so they can be used for longer. For more info, see the child car seat groups explained at the bottom of this page.

You’ll often see age ranges quoted along with the appropriate weights for a type of seat, but these are approximate; children grow at different rates, and it’s their weight that is crucial in deciding which seat to get if you’re buying using the grouping system.


Child car seats: how to buy and fit the safest seat

A new system of categorising seats according to the height of child they are appropriate for is being introduced. These seats conform to a new European regulation called i-Size.

All child car seats must adhere to either European regulation R44 or the new i-Size (or R129) rules. In time, i-Size will replace R44, although no firm date has been set for this yet. For now, the two sets of regulations exist alongside each other. At present, the i-Size regulation is only used for seats suitable for babies and young children up to 105cm tall (approximately 15 months old), but eventually seats for older children will also need to be approved to the i-Size standard.

All i-Size seats have Isofix mountings that slot into brackets on the car’s seats, which also reduces the chance of a seat being fitted incorrectly.

Child car seat groups explained

Seat group | Weight range | Approximate age

Group 0 | 0-10kg | Up to 12 months

Group 0+ | 0-13kg | Up to 15 months

Group 1 | 9-18kg | 1-4 years

Group 2 | 15-25kg | 3-7 years

Group 3 | 22-36kg | 6-12 years

Next: Which is safest: a forward- or rearward-facing seat? And what is an Isofix seat?>

Page 1 of 2