How to buy the best child car seat

Child car seats

How to buy the best child car seat

by Lisa Galliers

Buy a child car seat with confidence. Go armed with our top tips on what to look for and how to get the right advice in store.

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If you’re ready to hit the shops to buy your child car seat, watch our video above and then read our checklist below to make sure you get the right size seat. 

The video explains what you need to have to hand to tell the retailer and, just as importantly, what a good retailer should be asking you. You can also read on for more expert advice on choosing the safest car seat for your little one.

Our child car seats reviews reveal the seats that passed Which? crash tests.

Check your child

A few simple checks before you head to the shops will help you find the most suitable seat for your child.

1) Measure your child

Make a note of the weight of your child and how tall they are, as this will determine what seat you’ll need to buy. Any good shop you go to will ask for this information.

Record the weight in imperial and metric units – people often use pounds and ounces but car seats are approved for weight groups in kilograms. Weighing your child in both will avoid making mistakes when converting from one unit to another. Measure their height in centimetres.

2) Check your child in his or her current car seat

If you’re changing from one seat group to the next, weight isn’t the only factor. Check the position of your child's head in relation to the top of the seat.

You should change from a rear-facing Group 0+ when the crown of your child's head is level with the top of the seat. A child’s delicate head is exposed to more severe injuries in a crash if it pokes up above the top of the seat.

For Group 1, 2 or 3 forward-facing seats you need to change up when your child's eye level is in line with the top of the seat, otherwise protection in a crash won't be so comprehensive. 

3) Remember age is just a guideline

Babies, toddlers and older children grow and mature at different rates and there can be big differences between the weight and height of children of the same age.

It’s better for your child to be in a lower group seat, near the top of the weight limit, than to move them up to soon.

Check your car

Not all car seats fit in every car. Check in your car’s manual or with the car manufacturer to see which child car seats are approved for use in your make and model of car, and don’t forget to check for any car the seat is likely to be used in.

Before you set your heart on a particular car seat, there are a few key bits of information about your car you’ll need to find out:

1) Does your car have Isofix?

If you have a relatively new car, it’s likely to have Isofix mounting points (most cars made since 2002 do). These are two anchor points hidden in the padding on the back seats of the car. Some are easier to spot than others. 

Isofix is the standard system for all new cars and car seat manufacturers, designed to make installing your child safety seat quick and easy.

If your car has Isofix we strongly recommend you consider a compatible seat and use the mounting system. It’s usually easier to secure than the seatbelt method, so you should have a higher chance of fitting the seat correctly.

2) Does your car have underfloor storage compartments in the rear?

Car seats that use a support leg, or ones that can be fixed onto a base that uses a support leg, can’t always be used if your car has underfloor storage compartments in the back.

This is because the underfloor storage cover isn’t usually strong enough to withstand the force of a crash and would affect the performance of the seat.

If you do have these, and your car manufacturer recommends you don’t use a seat with a support leg, then your car should have a top tether mount instead. 

3) Does your car have top tether mounts?

Since November 2012 all new cars should have a top tether mounting point. This is a third anchor point to fix a car seat to, to stop the seat tipping forward in an accident, if you can’t use a seat or car seat base with a support leg.

4) Does your car have front passenger airbags?

Do not put a rear-facing child car seat (infant carrier, Group 0+) on the front passenger seat, with front airbags activated. Your child could be seriously injured by the force of the airbag going off during a crash.

You can use the front seat with an infant carrier if you can deactivate your front passenger airbag – check your car’s instruction manual to see whether this is possible. Check with your insurer whether deactivating the airbag affects the level of your insurance cover, too.

Still need more advice about the different ages and stages of child car seats? Head over to our choosing the best car seat - getting started guide.

Consider your lifestyle

Finding the right child car seat to transport one child in a single car is relatively easy – but finding one that will fit in with the whole family’s lifestyle is more of a challenge.

Read our top tips on things to think about before heading to the shops, so that you can give the car seat fitting expert as much information as possible – it will help them choose and fit the right seat for your family’s needs.

1) Will the car seat be used in other cars?

You need to know whether the cars you most commonly use have Isofix mounts, or whether you'll need a seat that can be fitted with a seatbelt. Think about the cars used by grandparents and childminders if they’ll use your seat.

2) How many children do you transport?

Fitting two or more child car seats in a car can be difficult, so make sure you mention the other children you transport regularly.

3) How tall are the parents?

Tall front seat passengers can affect how much space there is for a rear-facing child car seat or foot prop in the back. This could affect which seat you use for your child car seat when the whole family is travelling.

4) Make a shortlist

Take a look at our Best Buy child car seats that offer your child best protection and be easy to install.

Having some idea of what you want in advance helps you make the right decision when you are in the store. You can check on retailer websites whether they tend to stock the seats you want in store.

5) Arrange a fitting appointment

Some retailers offer fitting services. Phone the store before you go to find out if you can book an appointment so you can be sure to get help from their trained child car seat fitter to choose a suitable seat and show you how to fit it properly.

Going to the retailer

Our car seat retailer investigations revealed that some retailers don’t always offer the best service, and some fitters can offer poor advice. We’ve been working with the retailers investigated to improve staff training, and we would still advise you to go and get a car seat fitted in store.

But, we want you to be prepared. Go armed with:

In a good store, they should ask you several questions to help guide your purchase, including:

How much does your child weigh?

Your child’s weight is the deciding factor when it comes to selecting an appropriate seat. Without this information the assistant can't give you sound advice.

A good retailer will recommend keeping the baby rearward-facing for as long as possible. For an infant carrier this will be 13kg and for a rearward-facing Group 1 seat 18kg.

Despite guidelines, 9kg is far to small for a baby to go forward-facing, so challenge anybody who suggests turning your baby too soon. 

Moving a young baby to a forward-facing seat too early opens them up to all sort of risk of serious injury should you be involved in an accident. 

48%Parents incorrectly think it's safest for a nine-month-old baby to travel facing forwards.

How tall is your child?

If you are changing from one group of seat to the next, any retailer should ask about your child's height, relative to the top of the seat. If the crown of your child’s head is level with the top of the Group 0+ seat, your child is ready to move up.

For Group 1, 2 and Group 3 your child is ready when his or her eyes are in line with the top of the child seat (or higher).

What cars are you planning to use the seat in?

Not all seats fit all cars and, while some car seat manufacturers list which models fit which cars, you should double check before you buy. You can do this by checking the manufacturer’s website or when you try the car seat in your car before you buy.

Finally, the assistant should also be able to explain the features of any seat stocked by the retailer. The best assistants have knowledge of seats they don’t stock as well, so they can advise about the pros and cons of different approaches.

Demonstrating the child car seat

Once you’ve established the seats you’re interested in are suitable, ask the assistant for a demonstration on the in-store rig. This will allow you to see how the seat fits and adjusts, without the complexities of being in the confined space of a car.

Have a go at strapping your child into the seat and make sure you can adjust everything that’s likely to need adjusting during the time your child will be using it.

Adjustments are likely to include:

  • tightening the harness
  • reclining the seat to allow kids to sleep more comfortably
  • changing from rearward to forward facing (if applicable)
  • adjusting the height of the harness
  • removing and reattaching padding and inserts for infants
  • removing harnesses completely (multi-group seats)
  • adjusting headrests and any side padding.

Once you’re happy that the seat seems right for your child, ask for a demonstration in your car, so you can see that it actually fits. Trying a child seat in your own car is absolutely essential.

Sometimes, the angle of the car’s back seat or the position of its seatbelt mountings and buckles can get in the way of a good seat, making it useless.

Strap your child in and have a go at making all the adjustments. Make sure you’re happy with the fit of the seat in the car and your child in the seat.

Again, this is your chance to ask the retailer questions before you are on your own at home with the seat and a confusing set of instructions.

Only when you’re satisfied that the seat works for you, your child and your car, are you ready to buy.

Free car seat fitting checks

Some local councils hold regular car seat fitting clinics where you can get the fitting of your seat checked by trained fitters. Look on your local council website, or check local press for details of car seat fit clinics. 

Other organisations, such as Child Seat Safety and Good Egg Safety, also run free car seat check days around the UK.