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When we go out to purchase a car seat we often look at the height and the weight capacity of the seat. Even when looking on car seat manufacturer websites they often cite the height and weight limits front and center but don’t mention anything about torso height until you dig a little deeper into their manual or website. When three out of four car seats are being used incorrectly, I think this is a problem. You could have your seat installed perfectly but you must also use the seat correctly.
Take my two children as the perfect examples of torso height differences. Red’s height is all in his legs with a relatively short torso where K-Dub’s height is in his torso. Because of this he is outgrowing seats faster than Red did even if Red was physically taller at the same age. K-Dub passed his Britax Boulevard’s rear facing limit before his third birthday at about 37″ tall even though the Britax site says the seat will fit up to 49″. Why? Because he has a long torso.
Instead of following the manufacturer’s height limit alone, please keep these tips in mind to determine whether your child is too tall for his or her car seat:
Torso height while rear-facing
If your child’s head is within 1″ of the top of the seat then they are too tall and must be moved to a convertible car seat or turn around forward facing if they are already in a convertible seat. (check your seat’s manual. Some seats are within 1″ of the top of the shell and others are 1″ within the top of the headrest). See this post for photos: Are Britax seats the best choice for extended rear facing?
If you prefer to keep your child rear facing (the longer the better) then you must buy a new seat. To continue to use the seat rear facing when your child is too tall is dangerous and means you are using your seat incorrectly which could lead to injury or death.
Torso height while forward-facing
The general rule of thumb to determine if your child is too big for their forward-facing car seat is to see if the tops of their ears are above the seat’s shell (or headrest depending on the seat. Check your manual) and/or their shoulders are above the top harness slots. If one or both of these things are true then you must put your child in a booster seat or buy a new car seat with a longer shell.