Australian Height Makers

In 2010 Australia’s car seat standard AS/NZS 1754 changed from weight based (0-9 kg, or 0-12 kg) capsules, (0-18 kg) convertible, (14-26 kg) booster and (14-32 kg) harness to height based using visual height markers at the child’s shoulder. The markers indicate minimum, maximum and when to change to forward facing, or booster mode (depending on the seat).

These markers are designed to enable parents to correctly use car seats quickly and visually no longer having to base it on the child’s weight – which can differ daily based on the child’s clothing, meals they’ve eaten, growth spurts etc.

While the makers do make it easier for some, as the standard specifies that markers need to sit between X & Y heights some seats will last longer than others. It pays to check your child in the seat before buying and base your decision on what will give you best value for money. It goes without saying that some seats will give you lots of room for less cost than other seat and vice versa.

It’s important to also note that the usable height by the child may change once the seat is installed in the car, play around with upright and reclined installs to see what changes you may get. Some seats once turned forward (even though the child is at the “turn” marker”) may show the child as “under” the marker. By law in Australia the child must not be turned before 6 months of age, we in NZ know better and encourage you all to keep using the seat until your child reaches the top of the marker.

The images below show some of the markers you may see on all car seats from capsules to booster s (the Australian market no longer include half boosters at all). These are always visible to the left side of the car seat as you look at it, some seats have them on both sides.

The markers can be deceptive though as the shoulders are naturally slopped, children slouch when relaxed or sleeping and inserts that come with the seats can raise children giving the impression that they are ready to turn, or move out of the harness when they may in actual fact have another 6 or so months use in the harness.

Our understanding of the markers as set by Australian Standards is that they must be placed at a minimum height. There is a requirement of around 32-35 cm for the lowest maker on a convertible car seat. There appears to be no rules around lining the harness up with the shoulder slots (on models with re-thread harnesses), and where the highest makers are placed. (Someone in the know is welcome to correct me on this if they have the correct information).

Our thoughts are that the system as we wish to call it, takes the guess work out of “when can my child use X seat” especially great for grandparents, caregivers and others not often transporting the child, BUT, yes there is a “but”, the markers seem to differ greatly from seat to seat, with the wording “MUST BE ABOVE/BELOW THIS LINE”, on a white label with black text, a dotted line, and a box around the text, which line exactly, this is part of the guess work, secondly the distance between markers, between seats, between brands, between companies seems to differ greatly also.
Some manuals state that you can go up to 1 inch (2.5 cm) above the marker, yet the wording of “must” makes me picture Police slapping well-meaning parents with fines as Juniors shoulder sneaks up  above said maker and is deemed to be using the seat “incorrectly”.

Finally I am still concerned not knowing what weight the seat will tolerate safely, given children differ so much in childhood with some 2 year old toddlers weighting as much as 18 kg, and some school age children weighing as little at 36 kg at 9 years old, yet still fitting under the marker, when does a child become too heavy to be safe in their car seat? We’d love to see moves similar to that in the US on their combined booster seats where children need to be 2 years of age AND a minimum of 22 lb BEFORE using that seat, this gives me a better idea of when a child should ride rear or forward facing and not be placing kids into big seats too early.


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Expressions expressed in this Blog are that of our own and not influenced by a third party or sponsoring company. Images used on this page are our own, stock photos, or images used with parents permission. Please do not use without permission.

Bubble Bum Boosters Save Room, Time and Money!

Carpooling using booster seats

Are you driving carpool this year and wondering how you are going to fit 3 booster seats across the back of your minivan? Trying to fit multiple car seats & booster seats can be a challenge – even in a big vehicle like a minivan.

Before you rush to buy a booster for carpool…
Kids, especially younger ones, are safer in a 5-point harness. Don’t rush to “graduate” your child to a booster seat. Kids who are AT LEAST 15kgs AND AT LEAST 4 years old can start using boosters. Remember also that kids should ride on a booster UNTIL they can pass the 5-step-test (usually age 8-10).

Research in New Zealand and Australia shows that children need to use a booster seat until somewhere between 8 and 12 years of age (Elizabeth Segedin, 2006).

  • All 4 and 5 year olds required a car seat or booster seat
  • 90% of  6, 7, and 8 year olds required booster seats
  • 50% of  9 and 10 year olds
  • 10% of 11 and 12 year olds still required booster seats

Which booster is the narrowest?

The BubbleBum is very narrow at just 33 cm wide. The Bubble Bum is an inflatable booster and weighs only 450 g, so it’s perfect for all sorts of travel and carpool situations. It has no armrests, so it fits more easily in tight spaces than most traditional boosters. The missing armrests also allow kids to more easily see where to buckle the seat belt, which means they’re more likely to be able to buckle themselves in–definitely a plus in carpool situations! The BubbleBum inflates in seconds for use in your car and then deflates quickly for storage in your garage or for transport in your child’s backpack.

BubbleBum means it is possible to fit 3 across the back seat in most vehicles.

**Note: These are all BACKLESS boosters. In order to use a backless booster, the vehicle seat back MUST come up to at least the top of the child’s ears in order to provide adequate head support. If the vehicle seat back does not come up to at least the top of your child’s ears, then your child must use a high back booster.

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Blog written by Kelly Good (Bubble Bum).