How Long Do Car Seats Last & When Should you Change a Baby Car Seat?

Axkid Minikid 2.0 installation in car

Children grow at different speeds. When looking at guides on child car seats, these are often based on a 50th centile child. Therefore, a method to estimate how long a children’s car seat will last could be to look at your child’s rate of growth on his/her centile chart (in your red book). This will show the line of your child’s growth and give you a guide as to when he/she will reach the maximum weight or height for your chosen seat.

If your child is high on the centile chart, 90th or above, you can expect your seat to last approximately a year less than the guidelines for that seat. If they are 25th centile or below, you will probably get a year longer in the seat than it states.

How do I know if my child has grown out of their car seat?

Generally, child seats are either categorised by weight or height, so looking at the label on the seat will help you to decide. An infant carrier (Group 0+) seat normally lasts up to 13kgs (R44) or 76-87cms (R129).

Some questions you should ask:

  • Is their head crowning over the top of the seat?

For child seats (Group 1), this would normally occur at 18kgs or 105cms. A guide would be when their eye level reaches the top of the seat.

For High Back Boosters (Group 2/3), the law states that they are required until your child reaches 135cms in height. We would recommend 150cms if possible, but look at the child sitting without a seat:

  • Is the car seatbelt placement in the correct position across the hip?


  • Is the shoulder belt correctly aligned across the breastbone?

If they look comfortable and the belt is well positioned, then the child could travel without a car seat. If in doubt, it’s best to keep using the booster seats a little while longer. Come see us in store for a second opinion.

At what age can my child move out of their infant carrier?

It depends whether you’re using a seat that’s sold by weight (R44), or an i-Size seat that’s sold based primarily on height. If you’re using a seat that’s sold by weight, your baby should move to the next stage seat when he/she weighs more than the maximum limit for the seat, or when the top of his/her head is level with the top of the seat.

How long does my child need to use a car seat by law?

The law requires child seats to be used until the child is 135cms tall or 12 yrs old in the UK, this is different in some other European countries. Before you stop using a child seat, look at the placement of the seatbelt on the child. Is the lap part of the belt sitting across the child’s hip bone and the diagonal part across the chest? You might find that in one car the seatbelt placement is fine but another it’s not. It is preferable to use a highback booster until they are 150cms, just to be safe.


Do not hesitate to get in touch with a member of our team if you have any more questions.

Book a consultation with one of our expert car seat specialists today.