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It might take you a while to install an infant car seat for the first time (and base if you’ve bought one). For some reason, it can be very fiddly trying to attach the lower anchors properly, or using the seat belt correctly. Furthermore, once you think everything is in place, you might notice the car seat slides around a bit. Is this ok? Or should it be a lot tighter and held in place? Let’s answer this question in more detail.
Should a car seat move side to side? Are they supposed to wiggle?
You might be surprised to know that it’s ok for a car seat to move around a bit, but no more than an inch on each side. In the event of a crash, having a bit of movement allows the car seat to move with the force of the collision, which can reduce the impact on your baby. But it shouldn’t be installed too loosely, as your baby can collide into other parts of the vehicle so the risk of injury increases.

Can a car seat be installed too tightly?
It’s actually extremely difficult to install a car seat too tightly, unless you’re using special tools. This is because there is a bit of give in the seat belt. Furthermore, even if you were able to secure the car seat very tightly, this is riskier for your baby as they will receive more of the force during any collision.
How do I stop my baby’s car seat from sliding?
If you’ve installed the car seat correctly, using either ISOFIX, LATCH or just a seatbelt, there’s no way it should be sliding around a lot. Check the manual to see if you’ve installed things correctly. Sometimes a car seat base can help. If the car seat is still moving around too much, which is more common with leather seats, then you can put a seat protector or towel underneath. Check the car seat instructions to see if this allowed though.
How do I know if my car seat is installed correctly?
Unfortunately an incredible 85% of car seats aren’t installed correctly. This is remarkable considering all the safety features included on car seats which should indicate if there is a problem. However, often the main reason is having a car seat that doesn’t fit properly in the vehicle. Also, another reason is having straps which are too loose on your baby.
Make sure the car seat is installed properly so it won’t wiggle around too much and the harness is sufficiently tight. Using a car seat base can help, as many have bubble indicators or lights to indicate if you have installed things correctly.
How do I know if the harness is tight enough?
The general rule is that you should be able to just fit 2 fingers between the straps and your baby’s body. Another approach is to do the pinch test. Here you put your fingers on the harness near the child’s collarbone. If you can get a good pinch between your fingers with the strap in between, it’s too loose. If you can’t get the strap to pinch between your fingers, then it’s probably tight enough. Here’s a video demonstration.
In most cases, parents are usually guilty of not tightening the straps enough.
How do I keep my baby’s head from slumping in the car seat?
A head slump is where the chin moves forward towards the chest, usually when a person falls asleep. When adults do this, they usually wake up or try to bring their head back, but babies can often stay in this position. It’s only an issue for newborns who don’t have the muscles in their neck to bring their head back, and in the worst case scenario it could affect their breathing.
To counteract any chance of your newborn’s head from slumping, you need to ensure the car seat is reclined as much as possible for their age (usually around 45 degrees). Some car seats can even let you know if the car seat is at the right angle for newborn babies. You should also check their head is properly supported and they are properly secured in the harness.
Where is the safest place to put a car seat?
The safest place for a car seat is in the middle of the rear seats, although this isn’t a practical option for many families if they have more than 1 child. A middle seat position ensures your baby is better protected from side collisions. However, make sure you can properly install a car seat there using ISOFIX or LATCH.
How do you adjust the angle of a car seat?
You want the car seat to be angled at around 45 degrees for newborns, before moving it more upright to around 30 degrees as they get older. Some car seat manuals will state what recline position your baby should be in at various stages throughout the first year.
Here’s a great video showing how you can adjust the angle of a car seat.
Can you put a towel under a car seat?
If your car has leather seats, you might be concerned that an infant car seat can damage the material. In some cases, you might be able to put a towel or seat protector underneath, but it’s best to check with the instruction manual. If you can do it, you’ll probably want to lie the towel flat rather than folded up as this can cause the car seat to wobble more and be less stable.


Graham is a father of two who founded Dadometer to share his parenting journey with other moms and dads.