When can a child stop using a booster seat weight

Many parents wonder if and when their tall young child is ready for a booster seat, or if there's an age requirement for switching. It's easy enough to check the weight and height limits of various boosters to see if your little one will fit according to manufacturer instructions. But, many parents don’t realize that there is also a maturity requirement it's important to meet before riding in a booster as well.

Before deciding whether your child is ready to move on from a car seat to a booster, it helps to understand the difference between the two. Car seats use a five-point harness to restrain the child. A booster seat adjusts the position of the vehicle’s seat belt to fit safely across the child's torso and legs as a restraint.

Booster seat age refers to the age of a child at which they are ready to move from a car seat to a booster seat. The appropriate age is generally at least 4 years old, but for various children may be a few years older. In fact, it's safest for most kids to remain in a 5-point harness car seat until age 5 or 6.

Verywell / Brianna Gilmartin

The American Academy of Pediatrics (AAP) recommends that kids use a car seat until they reach the maximum height or weight for that five-point harness, which is often older than many parents assume. Usually, kids aren't ready to transition to a booster until at least age four, according to the National Highway Traffic Safety Administration (NHTSA).

Three-year-olds are not ready to ride in a booster seat, even if they fit within the manufacturer's height and weight guidelines. After the age of 4, if you can safely keep your child in a harnessed car seat for a while longer, do it. Research shows that kids are typically safer in car seats than in boosters.

To sit in a booster seat, children should:

Be mature enough to sit properly in the booster for the entire trip (no slouching, no leaning over, no messing with or unbuckling the seat belt)
Have exceeded the height or weight limits on their harnessed car seat
Ideally, be at least age 4 or older

Many convertible and harness-to-booster car seats have harnesses rated to hold kids up to 65 pounds. In fact, children in the U.S. today can often stay in a harnessed car seat until age six or beyond. Thanks to advances in car seat safety technologies, four-year-olds that might have been moved into a booster 10 years ago can still safely ride in a rear-facing car seat.

Even fairly tall children can remain rear-facing through toddler years and then switch to a forward-facing harness until kindergarten age. For most kids, even those in the 95th percentile for weight or height, there shouldn’t be a necessity to move to a booster before age 4.

If you can wait to switch you should, as kids are safer in 5-point harness car seats than in boosters. The truth is that any step up in car seats—from rear-facing to forward-facing, from the harness to booster—is actually a step down in safety. The 5-point harness spreads crash forces over more points on a child's body, lessening the potential force any one part of the body must take in a crash.

While some high-back booster seats have a minimum weight of 30 pounds, kids should weigh at least 40 pounds before riding in any booster seat.

From a practical standpoint, it is easier to have the child sit properly when in a car seat than in a booster, which is important because it keeps kids safely contained and limits distraction to the driver. In a booster, the child can unbuckle themselves more easily. They can also lean and slouch, which is dangerous. They can't do that in a car seat when the 5-point harness is properly adjusted.

The seatbelt cannot protect a child who is not in the proper position. Most children cannot be expected to sit routinely properly until at least five years old.

Many parents find that their child is actually much older than four before they can be expected to sit still in a booster. If your vehicle has lap-only seatbelts in the rear seats, keep your child in a harnessed car seat as long as possible. Harnessed seats can be installed with a lap-only belt.

Booster seats absolutely must be used with a lap/shoulder belt. Extended harnessing, or using a harnessed car seat with a higher weight limit, is vastly preferable safety-wise to moving a child into a lap-only seatbelt with a booster.

If you have a pre-2008 vehicle with a lap-only belt in the center, it is important to know that car seats can safely go there but boosters and big kids should not. Boosters and big kids need the protection of a shoulder belt. Therefore, if you need to have a kid ride in the center, make sure to use a car seat with a 5-point harness there.

If you think your child is outgrowing their harnessed car seat, first be sure that you're checking the right signs to judge the fit. Most children outgrow harnessed car seats by height long before they outgrow by weight, particularly with the 65-pound seats. When your child is forward-facing, the harness slots should be at or above the child's shoulders. When the shoulders are above the top slots, it's time to change seats.

A forward-facing car seat is also outgrown by height when the tops of the child's ears reach the top of the car seat shell unless the manufacturer states otherwise in the instructions. When checking the weight limits of the car seat, be sure you're looking at the forward-facing harness weight limit, not the booster weight limit (if it is a harness-to-booster seat).

There are many harness-to-booster car seats available today with a higher harness limit that later become booster seats. These can be a good option because they allow you to avoid buying another car seat and then a booster. Look for a car seat with a higher harnessed weight limit and a higher top shoulder strap height. This will allow the seat to be used longer in car seat mode (and likely, but not always, in booster mode, too).

The range of car seats available today means no family should struggle to find even a budget model that allows their child to remain safely harnessed to a minimum of age five, and most likely far beyond that.

Do you have more questions or concerns about whether your child is riding safely in the car? Visit a nationally certified child passenger safety technician (find one via SafeKids or the National Highway Traffic Safety Administration) to check the installation and usage of your child’s car seat.

It happens in the blink of an eye. One minute you’re bringing home a tiny baby in an infant car seat, and the next you’re wondering whether your big kid is ready to move out of a five-point harness to a belt-positioning booster seat. Children outgrow their car seats at different rates, but contrary to popular belief, the right time to make the switch has little to do with age. So how do you know when your child is ready for a booster seat? Here are some guidelines for making the switch safely at the right time for your little one.

Is My Child Ready for a Booster Seat?

The safest way for your child to ride in a vehicle is to remain in a five-point harness until they exceed the maximum height and weight requirements of their car seat. Many convertible car seats and harness-to-booster car seats on the market can accommodate children up to 65 pounds. But if you–and they–are ready to move on to a belt-positioning booster seat, make sure your child meets the following booster car seat requirements first.

Age and Car Seat Chart

1. Age.

Each state has its own laws and regulations for booster seat age and weight requirements. What is the law for booster seats? Always check your state’s requirements! That way, you’ll be best informed before moving your child into a different type of car seat. Most state laws and booster seat manufacturers require children to be at least 4 or 5 years old before using a booster. However, age isn’t as important as the other three factors.

2. Weight.

Even if your child is technically old enough to legally ride in a booster seat, they may not weigh enough to safely sit in one. At a minimum, your child should weigh at least 40 pounds before using a belt-positioning booster car seat.

3. Height.

The height of your child is of equal importance to weight when deciding whether they’re ready for a booster seat. You can safely make the switch only if your child is at least 35 inches tall and can sit in the booster seat with their back against the vehicle seat and their knees bent comfortably at the edge of the seat cushion.

4. Maturity.

Some 4-year-olds may be mature enough to properly sit in a booster seat for the entire car trip with the seat belt correctly positioned across the chest and shoulder, but many will be much older. Your child can safely sit in a booster seat only if they can ride without slouching, leaning to the side, or tucking the shoulder belt under their arm or behind their back.

You know your child best. If you can’t rely on your child to sit properly in the booster seat, you can’t rely on the car’s seat belt to properly restrain them when it really counts.

When to Stop Using a Booster Seat

Just as there are requirements for when a child is ready to move into a booster seat, there are also rules for when a child is able to stop using a booster seat altogether. And these rules may surprise you. Once again, the laws and requirements are different for each state, but typically, your child should remain in a booster until they reach the age of eight and a standing height of at least 4 feet 9 inches. Many children won’t safely be able to ride in a car without a booster seat until they’re 10 to 12 years of age.

The best way to decide if your child can safely ride in a belt-positioning booster seat or without a booster seat at all is to check the position of the seat belt. Does the seat belt sit across the middle of the chest and shoulder without cutting into the child’s neck? Can the child sit comfortably with their back against the seat and their legs bent at the knee over the edge of the seat? Is the lap belt low and snug against your child’s upper thighs? If so, it’s a good fit.

Ready to make the switch? Learn about the pros and cons between the different types of booster seats so you can make the best decision for your child. And remember, the best type of booster seat is one that fits your child and safely secures them while traveling.