What Are The Car Seat Weight Limits?

Understand the weight limits for your car seats. Each of the following baby car seats and kid’s booster have their own minimum and maximum weight limits.

When choosing the right car seat for your little one, the maximum and minimum weight limit is the most critical factor. Each type of car seat is designed to support a passenger within a defined weight range.

This article presents 22 different car seats, including all types. I created this guide to help you out in determining the best car seat type and model.

To guide us, I included a table showing the weight limit for each model. I also had the ideal age for the products.

This guide will cover the weight limit for:

• Car Seat in general
• Rear-facing Car Seat 
• Front-facing Only Car Seat 
• Convertible Car Seat
• 3-in-1 Car Seat

If you have more questions about the car seat included in the table chart, I also added a buying guide section to help you select which car is more appropriate for your family.

Quick Overview of the Different Car Seat Types

First, let’s be clear about car seats for kids. When we talk about car seats, we aren’t referring to only one type of product. Besides the variety in brands, there are several types and models. 

If you already know the difference, click here to jump to the next section!

If you’re not yet familiar with car seats and boosters, the number of options can be a bit overwhelming.

Rear-facing car seats: Infants and toddlers use rear-facing car seats, for example. These are built solely for the little ones with necks and backbones not strong enough to support them. See weight limit here!

Forward-facing car seats: Forward-facing models are appropriate for slightly older and heavier kids. These ones also have built-in harnesses since your kid won’t use the seat belt yet. See weight limit here!

Convertible car seat: Meanwhile, convertibles, 2-in-1s, and all-in-ones combine some or all types in one product. See weight limit here!

Booster seats: Booster seats are the one last transition before your child can be secured by a seatbelt.

Before each transition phase, it is strongly advised to maximize the seat’s weight limit. And make sure your child meets the minimum weight limit of the new car seat or orientation before moving on.

Minimum & Maximum Car Seat Weight Limit

Overall, the minimum weight limit is 4 lbs. (1.8 kg). This means a newborn baby weighing 5.5 to 7.5 lbs. (2.5 to 3.5 kg) can use several of the car seats included in the chart. On the other hand, the maximum limit range is between 100 to 120 lbs (45.5 to 54.5 kg). These car seats and boosters are most suitable for kids 12 years of age or more.

From the table, we can conclude that children from ages 0 to 12 can use car seats and boosters listed to help secure them in the car.

Weight Limit		Overall		Rear-facing		Forward-facing
Car seats	Unit	Min.	Max.	Min.	Max.	Min.	Max.
Graco Extend2Fit Convertible Car Seat	lbs	4	65	4	50	22	65
	kg	1.8	29.5	1.8	22.5	10	29.5
	age	0	10	0	7	1	10
Graco Tranzitions SnugLock 3 in 1 Harness Booster Seat	lbs	22	100	22	65	40	100
	kg	10	45.5	10	29.5	18	45.5
	age	1	12	1	10	5	12
Graco SnugRide SnugLock 35 Elite Infant Car Seat	lbs	4	35	4	35	n/a	n/a
	kg	1.8	16	1.8	16	n/a	n/a
	age	0	4	0	4	n/a	n/a
Safety 1st Grow and Go All-in-One Car Seat	lbs	5	100	5	40	22	65
	kg	2.25	45.5	2.25	18	10	29.5
	age	0	12	0	5	1	10
Safety 1st Onboard 35 LT Infant Car Seat	lbs	4	35	4	35	n/a	n/a
	kg	1.8	16	1.8	16	n/a	n/a
	age	0	4	0	4	n/a	n/a
Safety 1st Grand Booster Car Seat	lbs	30	120	n/a	n/a	30	120
	kg	13.6	54.5	n/a	n/a	13.6	54.5
	age	3	12	n/a	n/a	3	12
Britax One4Life ClickTight All-In-One Car Seat	lbs	5	120	5	50	22	120
	kg	2.25	54.5	2.25	22.5	10	54.5
	age	0	12	0	7	1	12
Britax B-Safe Endeavours Infant Car Seat	lbs	4	35	4	35	n/a	n/a
	kg	1.8	16	1.8	16	n/a	n/a
	age	0	4	0	4	n/a	n/a
Britax Marathon ClickTight Convertible Car Seat	lbs	5	65	5	40	20	65
	kg	2.25	30	2.25	18	9	30
	age	0	10	0	5	1	10
Chicco KeyFit Infant Car Seat	lbs	4	22	4	22	n/a	n/a
	kg	1.8	10	1.8	10	n/a	n/a
	age	0	1	0	1	n/a	n/a
Chicco KeyFit 30 Infant Car Seat	lbs	4	30	4	30	n/a	n/a
	kg	1.8	13.6	1.8	13.6	n/a	n/a
	age	0	3	0	3	n/a	n/a
Chicco KidFit 2-in-1 Belt Positioning Booster Car Seat	lbs	40	110	n/a	n/a	40	110
	kg	18	50	n/a	n/a	18	50
	age	5	12	n/a	n/a	5	12
Clek Liing Infant Car Seat	lbs	4	35	4	35	n/a	n/a
	kg	1.8	16	1.8	16	n/a	n/a
	age	0	4	0	4	n/a	n/a
Cybex Aton M Infant Car Seat with SensorSafe	lbs	4	30	4	30	n/a	n/a
	kg	1.8	13.6	1.8	13.6	n/a	n/a
	age	0	3	0	3	n/a	n/a
Cybex Aton 2 Sensorsafe	lbs	4	35	4	35	n/a	n/a
	kg	1.8	16	1.8	16	n/a	n/a
	age	0	4	0	4	n/a	n/a
Evenflo Tribute 5 Convertible Car Seat	lbs	5	40	5	40	22	40
	kg	2.25	18	2.25	18	10	18
	age	0	5	0	5	1	5
Evenflo Big Kid Highback 2-in-1 Belt-Positioning Booster Car Seat	lbs	40	110	n/a	n/a	40	110
	kg	18	50	n/a	n/a	18	50
	age	5	12	n/a	n/a	5	12
Maxi-Cosi Pria 3-in-1 Convertible Car Seat	lbs	4	110	4	40	40	110
	kg	1.8	50	1.8	18	18	50
	age	0	12	0	5	5	12
Peg Perego Primo Viaggio 4/35 Nido car seat with load leg base	lbs	4	35	4	35	n/a	n/a
	kg	1.8	16	1.8	16	n/a	n/a
	age	0	4	0	4	n/a	n/a
Peg Perego Viaggio Flex	lbs	40	120	n/a	n/a	40	120
	kg	18	54.5	n/a	n/a	18	54.5
	age	5	12	n/a	n/a	5	12
UPPAbaby Mesa Infant Car Seat	lbs	4	35	4	35	n/a	n/a
	kg	1.8	16	1.8	16	n/a	n/a
	age	0	4	0	4	n/a	n/a
UPPAbaby Knox Convertible Car Seat	lbs	14	65	14	45	22	65
	kg	6.3	30	6.3	20.5	10	30
	age	0	10	0	6	1	10

Rear-facing Car Seat Minimum & Maximum Weight Limit

The rear-facing car seats are specially designed for children ages 0 to 4. The maximum limit ranges between 22 to 35 lbs. (10 to 16 kg). Depending on the brand, kids can use these car seats until they’re 12 months old or up to 4 years old.

All 9 rear-facing car seats in the chart can support a minimum of 4 lbs. (1.8 kg). It’s good news if you’re taking home a newborn from the hospital via your car.

Rear-facing Car Seats Have the Lowest Minimum and Maximum Weight Limits

Rear-facing car seats have a lower weight limit because these are meant for really young passengers. These are supposed to protect infants’ and toddlers’ necks and back in case of a collision.

Experts recommend all infants and toddlers use rear-facing car seats. These are designed with safety, comfort, and mobility in mind. Consequently, rear-facing car seats are smaller and lighter compared to other styles.

Most have bases left in the car while parents carry the car seat or installed it on a stroller. However, it’s not advisable to use them for other than travel like sleeping or eating.

You should let your kid use a rear-facing car seat for as long as possible. Only transition to a front-facing car seat once your child reaches the weight limit between 22 to 35 lbs.

Front-facing Only Car Seat Minimum & Maximum Weight Limit

3 out of 5 models from this chart have a minimum limit of 40 lbs. (18 kg). The other ones, Safety 1st Grand Booster Seat and Graco Transition, are lower at 30 and 22 lbs. (13.6 and 10 kg). As for the max limit, half of the listed front-facing only seats are at 110 lbs. (50 kg), while the other half is at 120 lbs. (54.5 kg).

Front-facing Car Seats Have the Highest Minimum Weight Limits

These models are basically booster seats. Their minimum weight limits don’t go below 20 lbs. Except for Safety 1st and Graco that are suitable for toddlers, most of these were made for older children and not appropriate for infants and younger kids.

Convertible Car Seat Minimum & Maximum Weight Limit

When used as rear-facing: All of the converting car seats in the table have a minimum weight limit from 4 to 5 lbs. (1.8 to 2.25 kg). The max limit ranges from 40 to 50 lbs. (18 to 22.5 kg).

When used as front-facing: 5 out of the 7 convertible car seats in the chart have a minimum limit of 20 to 22 lbs. (10 kg). The maximum limit is 40 to 65 lbs. (18 to 30 kg).

Convertibles Have a Wider Range of Weight Limits

Like the regular rear-facing car seats, you can use a convertible in its rear-facing position for children as young as a few days old, weighing from 4-50 lbs. (1.8 to 22.5 kg). However, convertibles have a slightly higher max limit ranging from 40 to 50 lbs. (18 to 22.5 kg). Your kid can use these rear-facing convertibles past his toddler age, from 5th to 7th year.

Regardless of age, it is highly recommended to let your kid use a rear-facing car seat until he reaches the max limit. However, once converted to front-facing car seats, kids can use these products at the age of 1. That is given they meet the minimum weight limit, which is 20 to 22 lbs. (9 to 10kg).

As for front-facing car seats, your kid can use these ones until the age of 10. That is, if your kid does not weigh more than 65 lbs. (29.5 kg).

3-in-1 Maximum & Minimum Weight Limit

Just like convertibles, these booster seats from Safety 1st, Britax, and Maxi-Cosi can be used as rear-facing and front-facing car seats. In addition, they can transform into booster seats once your kid is tall and heavy enough. Consequently, these models have the highest maximum weight limit.

Rear-facing: Maxi-Cosi has the lowest limit at 4 lbs. (1.8 kg), while Britax and Safety 1st have 5 lbs. (2.25 kg). This makes these models suitable for infants. Their max limit also differs, at 50 and 40 lbs. (22.5 kg and 18 kg), respectively.

Front-facing/booster seat: When facing forward, Britax’s and Safety 1st’s have the lower minimum weight limit, at 22 lbs (10 kg). These are suitable for an average one-year-old. Meanwhile, Maxi-Cosi’s lower limit is 40 lbs. (18 kg), making it appropriate for an older kid at 5. At 120 lbs. (54.5 kg), Britax has the highest upper weight limit. Maxi-Cosi follows at 110 lbs (50 kg). Your kid can use both up until she’s 12 years old. Lastly, Safety 1st upper limit is 100 lbs (45.5 kg), suitable for a kid at age 10.

3-in-1s Have the Widest Range of Weight Limits

Like convertibles, these models can support children as young as a newborn. But since 3-in-1s can be transitioned to booster seats, their upper weight limits are also extended significantly.

Your kid can use these car seats for 10 years or more. So, investing in one will be an excellent idea.

Does the Type of Harness Affect the Weight Limits?

There is a correlation between weight limits and the type of harness a car seat uses. Based on the chart, models with limits from 4 to 65 lbs. all use built-in harnesses. Children must use the car’s seat belt for boosters reaching the maximum weight limit ranging from 100 to 120 lbs.

Let’s take a more detailed look and the sections below.

Built-in clip

For kids not tall enough to use the seatbelts, car seats are equipped with their own harnesses. From the models in the chart, these are the three types of car seats that use built-in clips.

Rear-facing only car seats: Built solely for infants and toddlers, all these have built-in harnesses. Their weight limits range from 4 to 35 lbs (1.8 – 16 kg). These harnesses are designed for both comfort and security. Depending on the brand, the materials used make them easy to clean. They are also adjustable to adapt to the height of your child.

Convertibles: Kids ages 0-10, weighing from 4 to 65 lbs, should use the built-in harnesses from convertibles, regardless of the car seats’ orientation.

3-in-1s: These car seats also use built-in harnesses for rear-facing and front-facing directions with the same minimum and maximum weight limit. But once they move to the booster seat phase, seat belts are required.

Seat belt

Eventually, your kid will reach the point where he will move on from the car seat harness to the seatbelt. From the chart, these are mostly during the booster phase.

Here are the two types that use seat belts as means of securing your child.

Front-facing only car seats/boosters: All these models require the use of seatbelts. Their weight limits range from 30 to 120 lbs. This means kids will use this type until their old and tall enough for seat belts.

3-in-1:  Once your child graduates from both the rear-facing and front-facing phases of these models, he will eventually use them as boosters. So with the same maximum limit as front-facing only car seats, your child will have to use the car’s seat belt.

Base

Britax B-safe is the only car seat base in the chart. Its weight limit is the same with rear-facing only car seats, at 4 to 35 lbs.

Which Brands Have the Widest Minimum & Maximum Weight Limit Range?

All the brands that have the most extended weight support are 3-in-1 car seats. They all transition from rear-facing to front-facing and then booster seats.

Here are the 3 brands and their range:

Which Car Seat Is Booster Seat Only?

Once your child has outgrown or exceeded the front-facing car seat’s weight limit, it’s time for him to use the booster. He will have to use this until he’s big enough to fit the seat belt.

Check this model out!

Which Car Seats Are 2-in-1s?

Children exceeding the max limit of rear-facing car seats can transition to 2-in-1s. Depending on the brand, kids as young as 3 or at least 5 can use these models as front-facing car seats. Once in the booster seat phase, these ones support max weight between 110 and 120 lbs (50 and 54.5 kg). 

These 3 booster seats are suitable for children up to 12 years of age.

Which Brands and Models Are Convertible Car Seats?

Like 3-in-1s, these car seats grow alongside your kid. Except convertibles don’t transition to booster seats. Among other convertibles in this list, Graco is the best in terms of weight limits, especially when rear-facing.

Here are the 4 brands with models in the same category:

Which Car Seats Are Rear-facing Only?

Drive your newborn baby home safely in these rear-facing car seats. The average weight limit range of these models is from 4 to 35 lbs.

Rear-facing only car seats are lightweight, easy to install, carry, and clean. Toddlers, up to 3 or 4 years can use these ones as well.

Of all the models and brands on the list, I find the ones from Chicco to be the best. They don’t only have the bells and whistles of most car seat models. These also come with sensors and apps helping you look after your little ones at the back. The other brands are also worth checking out as well.

Here are the 9 rear-facing only car seats from the list:

Takeaway

Car seats and boosters are essential when you have a car and a kid. Make sure to get one with limits that cover your child’s weight. Remember that weight and height (not age) should decide whether or not your child is ready to move on to a different car seat type.

Purchasing a convertible or a 3-in-1 is also a great idea if you want to make the most of your money. This way, you won’t have to worry about your child outgrowing the car seat.

Also, please use this article only as a source of general information about car seats and boosters. This is not intended as a guide on how to use each model. Always consult your user manual for the best instructions.