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What Is the Age and Weight Limit on Booster Seats in a Car?

My son is 3, and weighs 45 lbs. Because we just downsized vehicles, it left us with less space in the back seat, and I am wondering if he is ready for a booster seat instead of the full sized car seat. If not, no biggie, just a thought.

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Please keep him in a 5 point harness as long as possible.

www.kyledavidmiller.org has great information and also helps families who cannot afford to replace their car seats.

1 mom found this helpful

It is not 4 or 40 lbs it is 4 AND 40 lbs. The longer you can keep him in a 5 pt harness the better. It is just safer. My poor daughter is going to be in high school before she is 40 lbs-haha!!

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In CO your child must be at least 4 years AND 40lbs MIN.
Below is copied from BBC- just so more info

Why you should consider keeping your child harnessed past age 4 and 40 pounds in a car seat with a higher weight harness.

A younger child doesn’t have the mental maturity to understand that s/he needs to stay still in a booster. The shoulder belt must always stay on the shoulder to keep the child from being thrown forward in a crash. A parent who prematurely moves a child into a booster is often put in the position of constantly reminding (nagging) her child to stay in position to stay safe. The child will eventually tune out the parent and the parent will become frustrated. The child's safety is placed in the hands of the child. A car seat with a properly tightened 5-point harness allows a child to be a child: no nagging to stay in position, no worrying that the child doesn't have the seat belt on or is leaning over to pick up a toy.

5-point harnesses spread crash forces over a larger area and there are 5 points of protection on the child vs. 3 points with a lap/shoulder belt (1 shoulder and 2 hips). A properly adjusted harness is more likely to keep the child contained in the seat and not ejected, especially in a side impact or rollover. Sleeping is easier in a 5-point harness than in a booster.

Compare these 2 videos and watch how the dummy moves in each:

http://www.oeamtc.at/netautor/html_seiten/kisitest_2002/v... (This is a harnessed seat similar to what is sold in the US.)

http://www.oeamtc.at/netautor/html_seiten/kisitest_2002/v... (This is a booster similar to what is sold in the US.)

There are higher weight harness seats in all price ranges and some convert to boosters once kids reach the weight limit of the harness.

Videos dedicated to children who might have lived had they been harnessed (!Warning!!These are tear jerkers!):

Kyle David Miller: http://www.youtube.com/watch?v=azgBhZfcqaQ

Isabelle Broadhead: http://www.youtube.com/watch?v=y2LFo8vVi04

Toni Perry: http://www.youtube.com/watch?v=G59s3PjcntQ

1 mom found this helpful

It is not 4 or 40 lbs it is 4 AND 40 lbs. The longer you can keep him in a 5 pt harness the better. It is just safer. My poor daughter is going to be in high school before she is 40 lbs-haha!!

1 mom found this helpful

Please keep him in a 5 point harness as long as possible.

www.kyledavidmiller.org has great information and also helps families who cannot afford to replace their car seats.

1 mom found this helpful

My pediatrician just told me 4 years or 40 lbs (because we joked my son wouldn't be 40 lbs until high school so good thing he can "graduate" at 4 yrs!- he's 2 and has been between 20-23 pounds for a YEAR!)!

I believe the weight limit on most booster seats is 30 pounds and on some its 35, maybe 40. It usually states right on the box what the weight, height, age requirements are. Be sure to get one with a back that has a slot for the seat belt so you can get the seat belt in the right position. I know when we moved our oldest up I was kind of worried, but then he was involved in an accident and the only physical injury he had was a bit of a bruise on his shoulder where the seat belt kept him in place so I know they work.

Hi M. - I have a large 3 yr old as well. We have him in a backed booster right now because he is 41 inches tall and 44 pounds. We chose to move to a booster because he was tall enough and would keep the seat belt in place.

Part of your decision should include not only weight but also height. You might consider one of those little covers that snaps over the seatbelt to help keep it in good position.

We had a pickup w/an extended cab (no back doors) & a busted seat. So I wouldn't have to turn the baby's seat upside down to get him in & around the other full carseat, I put my 2.5 year old in a booster. By the time we got the minivan w/more space & more flying room in case of an accident he was 3 & big enough to be in his booster according to the box. They make boosters w/a 3 or 5 pt harness seat that you can pull straps out of when they're older, I use those til my boys are big enough-in my mind-to work the real seatbelt.


This will give you answers.

Although your son meets the weight requirement for a booster, I think he may be too short. Remember, boosters are to put children in a position where the seat belts fit them as they fit adults. I don't think a 3 year old will be near that mark.

Just hang in there for another year, if you were in an accident, a 5 pt. harness car seat provides far better protection for your little one.

I think my pediatrician said something about in addition to meeting the height and weight requirements, the age is important because of how a child's spine develops - but this was a discussion about going from infant to toddler seats so I'm not sure about booster seats. Maybe ask your doctor if your son is ready for a booster?

Although CO law is 4 years and 40 lbs. for a booster, I've heard that it is actually more ideal to transfer to a booster at 6 years and 60 lbs. Clearly some states have different laws, but the truth of the matter is a five point harness is by far the safest way to ride in a car. NASCAR racers have them for just that reason! If consumer industry could convince adults they were worth the hassle, we would all be tooling around in 5 point restraints. (Be an issue with a skirt, though, LOL!)

Not all seats take up the same amount of space. We have a Graco Nautalis (sp?) and it is fairly upright, allowing it to easily fit in the backseat. Her britax (in our other car) is much more slanted and therefore does not fit in small backseats. If space is an issue, go to a store that will allow you to try them out in your car. I've heard Babies R Us will do this, if you leave an ID and credit card while you are trying them. Or I suppose you could just measure the depth of your backseat and go from there.

Overall, I would encourage you to keep your child in a five point restraint as long as possible, as it is safer for all involved. If your little guy is kicking the seat in front, try putting him in the middle or behind the passenger seat so that you don't have to put up with it while driving. And, of course, you can move the passenger seat all the way forward if nobody is riding there. Good luck!

It is recommended that a child not be in a booster seat until 4 yrs and 40lbs. This is due to the bone structure and also you want your child to be able to sit upright (no slouching) and remain that way for the entire trip with no reminders. If a child slouches it can change the position of the lap part of the belt to going across the stomach which can cause internal injuries in a crash instead of across the hips and thighs (strongest bones and muscles in the body).

Personally I would recommend getting a Graco Natalus which is only 19.5 inches at the wides point in the seat (actually at the arm rests not the base which is only 17 inches). They are good for 6 years go to 65lbs in harness which should hopefully get you to at least 4 yrs (I am in kind of the same situation with a 2 yr old that weighs 35lbs) and than will go to either a high back or low back booster to 100 lbs.
Though unless your vehicle has high seat backs or a head rest you want to use a high back booster to give the head protection as low back boosters are designed to be used with vehicle seats that have high backs or adjustable headrests when you do switch to a booster seat.


A backless booster is 40 1bs and up. A booster with a back can be used starting when they are between 30 and 40 lbs. So he is probably big enough. The most important issue is to make sure the shoulder belt fits on his shoulder in the right spot. He shouldn't put the belt behind him and make sure he will leave the seat belt on.

I believe it is 4 years and 40 pounds in Colorado. Some states are 3 and 30 pounds for the high back booster. I have been told to keep them in a 5 point harness as long as possible.

I think the weight is 40 lbs.

I have a 3 yr old who is 33 lbs and 38 in tall. He wanted to be grown up and so when he was in his car seat he kept undoing the belt so I decided I'd get him a booster seat. His is just the seat part (money was a big issue). He loves it and leaves his seat belt on now. But he likes the freedom to be able to undo his own belt and get out of the car by himself (once I open the door) and he even can get in the car and buckle himself up by himself. In Utah there is no age limit (as far as know) just a weight limit for the booster seats themselves. I even got pulled over (I was speeding) and the police officer looked in the back seat and asked me if my oldest was in a booster seat (because he couldn't see it) and how old he was. I told him 3 and yes and he was fine with it.

I believe your son meets most booster seat recommendations for weight (I think most have a 40 lbs min requirement), but they also recommend that your child be a certain height as well. You'll need to check the booster seats guidelines for specifics. If you search online, most product details give you this information. I think most also recommend your child be at least 4 years old, but not sure how that matters if they child meets the height and weight requirements.
My daughter will turn five next month, but still doesn't quite meet the height or weight requirements for the backless booster seat we bought her earlier this year. Though she's been begging us to let her move to the new seat, we will not allow her to do so until she meets the requirements. Why sacrafice her safety?
On a related note... if you do decide to move your son over, both Consumer Reports and the National Institute for Highway Safety (the latter can be found online for free) have recommendations for the best (safest) booster seats.

You should call your local police and ask what the regulations are for car seats/booster seats. Thats what I have done in the past as it varies from state to state.

What I read said 4 or 40 pounds...I'm not sure if they have to be both or if just one is good enough.

Most boosters are for 40 to 100 lbs. The key is to get the high back booster until he is taller because it has the belt positioner for the shoulder strap. That way the seat belt won't be across his neck or face. Good Luck, it's a fun transition!

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