When considering how long a CR can be used, the tendency is to focus primarily on weight limits. But given the quantity of high-weight-harness (HWH) models on today’s market, most children will outgrow a CR by height before reaching the weight limit—sometimes long before.
It wasn’t always this way. Within recent memory, weight was nearly always the limiting factor, since infant CRs had 22-pound rear-facing limits, and forward-facing harnesses uniformly could be used to 40 pounds. But CRs today have been strengthened and are rated to be used at much higher weights for either mode, so the mind-set must shift to expecting most CRs to be outgrown by height.
Take, for instance, infant CRs that can be used to 30 or more pounds. Having the ability to use these CRs to higher weights is useful, but parents should not be misled to expect that their child is likely to ride in such a CR up to the top weight. According to the current growth chart from the Centers for Disease Control (CDC), a 50th percentile child of 30 pounds is over 2 ½ years old and 36 inches tall. Though seated height is what really matters, the fact that most infant CR instructions limit use to children 30 or 32 inches or shorter is a good indication that most infants will outgrow these CRs by height well before weight. In fact, an average 1-year-old is 30 inches and 22 pounds, so many infants fit a CR rated to 22 pounds for about as long as a model of the same length rated to 30 pounds.
Forward-facing CRs are the same in this respect. Our new product update (Safe Ride News May/June 2012 article, page 1) lists many new CRs that can be used to 65 or 70 pounds. According to the CDC, the average 65-pound child is over 9 years old and 53 inches tall, whereas an informal survey of manuals found that most CRs rated to 65 or 70 pounds are capped at 49 to 52 inches. This CR height range would more likely fit children of average height as they reach a weight of 50 pounds, rather than 65. (See the table below for height/weight information.)
So, though parents should be aware of the upper weight limit of the CR, it is as—or even more—important that they know how to determine when the child is too tall for the CR. Owner’s manuals will typically describe this as when the head is an inch below the top of the shell for rear-facing CRs and when the shoulders are above the top harness slots or the ears are above the top of the CR shell for forward-facing CRs.
That height limits may come into play before weight limits does not mean that CR height limits are overly restrictive. For instance, the CDC says an average 8-year-old is 50 inches tall, the upper height limit of many high-weight-harness CRs. Outgrowing the harness at this age aligns with AAP CR-use guidelines.