Infant Car Seat Size Explained in Detail by Age, Weight & Height

September 19, 2022March 27, 2023 by Egle Goleckyte

An infant car seat is a rear-facing car seat with a bucket-style shape that most parents utilize for up to age 2 of their baby’s life. After that, some parents prefer using convertible car seats. Either way, the National Highway Traffic Safety Administration demands you get a rear-facing car seat for your infant. But what about infant car seat size? All is explained by age, weight, and height.

Grabbing an oversize or undersized child rear car seat for your baby means they will strain to stretch or have excess space around them. This can be dangerous as your child has minimum safety without a perfect fit. You can consult a Child Passenger Safety Technician skilled in creating exclusive car seats for all infant sizes to avoid this.

Infant Car Seat Size Explained in Detail by Age, Weight & Height size-charts.com — _{Photo by Alexander Grey on Unsplash}

Do you want to learn how to find the right infant car seat size for your child? Read on!

Jump right into the Frequently Asked Questions

Table of content on baby car seat sizing

Infant Car Seat Size Chart
How To Choose the Right Infant Car Seat Size
Frequently Asked Questions

Infant Car Seat Size Chart

Infant Car Seat Size Limit Chart: BOYS

Car Seat Type	Age (Month)	Weight	Height
Rear-Facing Car Seat	6	21 lbs 9.5 kgs	28.5 inch 72.4 cm
Rear-Facing Car Seat	9	24.5 lbs 11.1 kgs	30 inch 76.2 cm
Rear-Facing Car Seat	12	27.5 lbs 12.5 kgs	32 inch 81.3 cm
Rear-Facing Car Seat	15	29.5 lbs 13,4 kgs	33 inch 83.8 cm
Rear-Facing Car Seat	18	31 lbs 14.1 kgs	34.5 inch 87.6 cm
Rear-Facing Car Seat	21	32 lbs 14.5 kgs	35.5 inch 90.2 cm
Rear-Facing Car Seat	24	33 lbs 14.9 kgs	36.5 inch 92.7 cm
Rear-Facing Car Seat	27	33.5 lbs 15.2 kgs	37.5 inch 92.3 cm
Rear-Facing Car Seat	30	34.5 lbs 15.6 kgs	38.5 inch 97.8 cm
Rear-Facing Car Seat	33	35.5 lbs 16.1 kgs	39.5 inch 100.3 cm
Rear-facing/ Forward-facing car seat	36	37 lbs 16.8 kgs	40.5 inch 102.9 cm
Rear-facing/ Forward-facing car seat	48	38.5 lbs 17.5 kgs	43.5 inch 110.5 cm

Infant Car Seat Size Limit Chart: GIRLS

Car Seat Type	Age (Month)	Weight	Height
Rear-Facing Car Seat	6	19 lbs 8.6 kgs	27.5 inch 69.8 cm
Rear-Facing Car Seat	9	22.5 lbs 10.2 kgs	29.5 inch 74.9 cm
Rear-Facing Car Seat	12	25 lbs 11.3 kgs	31 inch 78.7 cm
Rear-Facing Car Seat	15	27.5 lbs 12.5 kgs	32.5 inch 82.6 cm
Rear-Facing Car Seat	18	29 lbs 13.2 kgs	33.5 inch 85.1 cm
Rear-Facing Car Seat	21	30.5 lbs 13.8 kgs	35 inch 88.9 cm
Rear-Facing Car Seat	24	32 lbs 14.5 kgs	36 inch 91.4 cm
Rear-Facing Car Seat	27	33.5 lbs 15.2 kgs	37 inch 93.9 cm
Rear-Facing Car Seat	30	35 lbs 15.9 kgs	38 inch 96.5 cm
Rear-Facing Car Seat	33	36.5 lbs 16.6 kgs	39 inch 99.1 cm
Rear-facing/ Forward-facing car seat	36	38 lbs 17.2 kgs	40 inch 101.6 cm
Rear-facing/ Forward-facing car seat	48	44 lbs 19.9 kgs	42.5 inch 107.9 cm

Infant Car Seat Size Comparison Chart

Safe Car Seat Name	RF Weight Limit	RF Height Limit	Bottom Harness Slot	2nd Harness Slot	Closest Buckle Slot	Inside Hip Width
Baby Trend EZ Flex-Loc 32	5 – 32 lbs 2.3 – 14.5 kgs	32 inch or less 81.3 cm or less	8 inch 20.3 cm	12 inch 30.5 cm	5 inch 12.7 cm	10 inch 25.4 cm
Baby Trend Flex-Loc 30	5 – 30 lbs 2.3 -13.6 kgs	30 inch 76.2 cm	7.5 inch 19.1 cm	11.5 inch 29.2 cm	5 inch 12.7 cm	10 inch 25.4 cm
B-Safe	4 -30 lbs 1.8 – 13.6 kgs	32 in. or less 81.3 cm or less	5.5 in. 13.9 cm	11.5 in. 29.2 cm	4 inch 10.2 cm	9 inch 22.9 cm
Britax B-Safe 35	4-35 lbs. 1.8 – 15.9 kgs	32 in. or less 81.3 cm or less	5 inch 12.7 cm	7 inch 17.8 cm	4 inch 10.2 cm	8 inch 20.3 cm
B-Safe 35 Elite	4 – 35 lbs. 1.8 – 15.9 kgs	32 in. or less 81.3 cm or less	5.5. or 6.5 in. 13.9 – 16.5 cm	11.5 in. 29.2 cm	4 in. 10.2 cm	8 in. 20.3 cm
Britax Endeavours	4 – 35 lbs. 1.8 – 15.9 kgs	32 in. or less 81.3 cm or less	5.5. or 6.5 in. 13.9 – 16.5 cm	11.5 in. 29.2 cm	4 in. 10.2 cm	8 in. 20.3 cm
Chicco Keyfit 22	4 – 22 lbs. 1.8 – 9.9 kgs	30 in. or less 76.2 cm or less	6.5 or 8 in. 16.5 or 20.3 cm	10 in. 25.4 cm	6 in. 15.2 cm	9.75 in. 24.8 cm
Chicco KeyFit 30 infant car seat size	4 – 30 lbs. 1.8 – 13.6 kgs	30 in. or less 76.2 cm or less	6.5 or 8 in. 16.5 or 20.3 cm	10 in. 25.4 cm	6 in. 15.2 cm	9.75 in. 24.8 cm
Combi Shuttle 35	Birth-35 lbs. Birth – 15.9 kgs	33 in. or less 83.8 cm or less	8.5 in. 21.6 cm	14.5 in. 36.8 cm	5.25 in. 13.3 cm	8 in. 20.3 cm
Cosco Light n Comfy DX	4 – 22 lbs. 1.8 – 9.9 kgs	29 in. or less 73.7 cm or less	5.5 in. 13.9 cm	7.5 in. 19.1 cm	3.5 in. 8.9 cm	–
Cosco Light n Comfy LX	4 – 22 lbs. 1.8 – 9.9 kgs	29 in. or less 73.7 cm or less	5.5 in. 13.9 cm	7.5 in. 19.1 cm	3.5 in. 8.9 cm	–
Cybex Aton	4 – 32 lbs. 1.8 – 14.5 kgs	Up to 30 in. Up to 76.2 cm	7.5 or 8 in. 19.1 or 20.3 cm	10 in. 25.4 cm	6 in. 15.2 cm	9.5 in. 24.1 cm
Cybex Aton 2	4 – 32 lbs. 1.8 – 14.5 kgs	Up to 30 in. Up to 76.2 cm	7.5 or 8 in. 19.1 or 20.3 cm	10 in. 25.4 cm	6 in. 15.2 cm	9.5 in. 24.1 cm
Cybex Aton Q	4 – 35 lbs. 1.8 – 15.9 kgs	30 in. (1″ above head) 76.2 cm (2.5 cm above head)	7.5 in. 19.1 cm	12.5 in. 31.8 cm	–	9.5 in. 24.1 cm
Disney Baby Mickey / Minnie Light n Comfy Luxe	4 – 22 lbs. 1.8 – 9.9 kgs	29 in. or less 73.7 cm or less	5.5 in. 13.9 cm	7.5 in. 19.1 cm	3.5 in. 8.9 cm	–
Evenflo Embrace 35	4 – 35 lbs. 1.8 – 15.9 kgs	Up to 30 in. Up to 76.2 cm	6 in. 15.2 cm	8.5 in. 21.6 cm	4 in. 10.2 cm	9.5 in. 24.1 cm
Evenflo Nurture	5 – 22 lbs. 2.3 – 9.9 kgs	19-29 in. 48.3 – 73.7 cm	5.5 in. 13.9 cm	7.5 in. 19.1 cm	4 in. 10.2 cm	–
GB Asana 35 DLX	4 – 35 lbs. 1.8 – 15.9 kgs	32 in. or less 81.3 cm or less	6 in. 15.2 cm	11 in. 27.9 cm	4 in. 10.2 cm	9 in. 22.9 cm
GB Asana 35 LTE	4-35 lbs. 1.8 – 15.9 kgs	32 in. or less 81.3 cm or less	6 in. 15.2 cm	11 in. 27.9 cm	4 in. 10.2 cm	9 in. 22.9 cm
Graco SnugRide Classic Connect 22	5-22 lbs. 2.3 – 9.9 kgs	29 in. or less 73.7 cm or less	7.5 in. 19.1 cm	10.25 in. 26.0 cm	5 in. 12.7 cm	10.25 in. 26.0 cm
Graco SnugRide Classic Connect 30	4-30 lbs. 1.8 – 13.6 kgs	30 in. or less 81.3 cm or less	7 in. 17.8 cm	8.5 in. 21.6 cm	2.5 in. 6.4 cm	9 in. 22.9 cm
SnugRide Classic Connect 35	5-35 lbs.	Up to 32 in. Up to 81.3 cm	7 in. 17.8 cm	9.5 in. 24.1 cm	5.5 in. 13.9 cm	10 in. 25.4 cm
Hauck PROsafe35	4-35 lbs. 1.8 – 15.9 kgs	32 in. or less 81.3 cm or less	5.5 in. 13.9 cm	7 in. 17.8 cm	4 in. 10.2 cm	9 in. 22.9 cm
iCoo iGuard35	4-35 lbs. 1.8 – 15.9 kgs	32 in. or less 81.3 cm or less	5.5 in. 13.9 cm	7 in. 17.8 cm	4 in. 10.2 cm	9 in. 22.9 cm
Ingenuity InTrust 35 Pro	4-35 lbs. 1.8 – 15.9 kgs	32 in. or less 81.3 cm or less	5.5 in. or 6.5 in. 13.9 – 16.5 cm	11 in. 27.9 cm	6 in. 15.2 cm	–
Maxi-Cosi (Dorel) Mico AP	5-22 lbs. 2.3 – 9.9 kgs	19-29 in. 48.3 – 73.7 cm	7.5 in. 19.1 cm	10.75 in. 27.3 cm	3 in. 7.6 cm	11.5 in. 29.2 cm
Maxi-Cosi (Dorel) Mico Max	4-30 lbs. 1.8 – 13.6 kgs	19-32 in. 48.3 – 81.3 cm	7.5 in. 19.1 cm	8.75 in. 22.2 cm	4 in. 10.2 cm	10.5 in. 26.7 cm
Mia Moda Certo / Viva Supreme	4 – 22 lbs. 1.8 – 9.9 kgs	Less than 29 in. Less than 73.7 cm	6.75 in. 17.1 cm	12 in. 30.5 cm	4 in. 10.2 cm	–
Mountain Buggy protect	4 – 35 lbs. 1.8 – 15.9 kgs	32 in. 81.3 cm	6 in. 15.2 cm	11.25 in. 28.6 cm	4 in. 10.2 cm	–
Nuna Pipa	4-32 lbs. 1.8 – 14.5 kgs	32 in. or less 81.3 cm or less	6 or 7 in. 15.2 – 17.8 cm	9 in. 22.9 cm	5 in. 12.7 cm	–
Orbit Baby Infant Seat G3	4-30 lbs. 1.8 – 13.6 kgs	19-32 in. 48.3 – 81.3 cm	8 in. 20.3 cm	10 in. 25.4 cm	6 in. 15.2 cm	8 in. 20.3 cm
Peg Perego Primo Viaggio 4-35	4-35 lbs. 1.8 – 15.9 kgs	32 in. or less 81.3 cm or less	5 in. 12.7 cm	11.5 in. 29.2 cm	6.5 in. 16.5 cm	–
Safety 1st (Dorel) onBoard 35	4-35 lbs. 1.8 – 15.9 kgs	32 in. or less 81.3 cm or less	5.5 in. 13.9 cm	11.5 in. 29.2 cm	3 in. 7.6 cm	10.5 in. 26.7 cm
Safety 1st Light n Comfy	4-22 lbs. 1.8 – 9.9 kgs	29 in. or less 73.7 cm or less	5.5 in. 13.9 cm	7.5 in. 19.1 cm	3.5 in. 8.9 cm	–
Team Tex America Baby Ride	Up to 22 lbs. Up to 9.9 kgs	29 in. or less 73.7 cm or less	8.5 in. 21.6 cm	11.5 in. 29.2 cm	4.5-5 in. 11.4-12.7 cm	9 in. 22.9 cm
UPPAbaby Mesa	4-35 lbs. 1.8 – 15.9 kgs	32 in. or less 81.3 cm or less	5.5 in. 13.9 cm	10 in. 25.4 cm	–	–
Urbini Petal	4-35 lbs. 1.8 – 15.9 kgs	Up to 32 in. Up to 81.3 cm	6 in. 15.2 cm	11.5 in. 29.2 cm	4.5 in. 11.4 cm	10 in. 25.4 cm
~Baby Trend Flex-Loc 22 (discontinued)	5-22 lbs. 2.3 – 9.9 kgs	28.5 in. or less 72.4 cm or less	8 in. 20.3 cm	11.5 in. 29.2 cm	5 in. 12.7 cm	9.5 in. 24.1 cm
~Combi Shuttle 22 (discontinued)	5-22 lbs. 2.3 – 9.9 cm	29 in. or less 73.7 cm or less	8 in. 20.3 cm	11 in. 27.9 cm	5 in. 12.7 cm	11 in. 27.9 cm

How To Choose the Right Infant Car Seat Size

The right baby infant car seat size should allow space for your child to stretch. According to the Federal Safety Standards, the seat should also provide maximum comfort and safety for the baby.

It should be compatible with your vehicle seat to ensure stability and impact protection if there’s an accident or a swift stop. When checking the measurements, consider different parts of your infant’s body. For instance, the upper thighs, height, and weight. Then compare them to the minimum weight, maximum weight, minimum height, and infant insert availability.

Infant car seat size accessories are also essential when buying a rear-facing infant car seat. Some may alter the dimensions, for instance, the infant inserts can adjust the inside hip width when fitted. In addition, accessories such as harness straps, an anti-rebound bar, a five-point harness, and a shoulder belt provide extra protection for your child.

Depending on your child’s age, you can purchase a rear-facing car or convertible seat. Typically, a CPS technician will advise you to buy rear-facing seats for kids age 2 and below. Kids who are two years and above can use forward-facing seats comfortably.

Suppose you’re working on a tight budget; you can compare the price range of infant car seats size amazon or get second-hand car seats. Nevertheless, getting combination seats such as a rear-facing convertible seat would offer your toddler better protection and luxury if you can afford expensive seats like Evenflo Gold Revolve360.

Learn more about how to choose the right car seat for your infant (video)

_{General Car Seat Guide | Which Car Seat Do I Use Next? by The Baby Cubby}

Frequently Asked Questions

What size car seat comes after an infant?

The type of seat that comes after the infant period is the convertible and booster car seats. The forward-facing limits for kids older than infants are usually 40.5 inches and 16.8 kgs minimum. Hence, you should check the forward-facing convertible car seat features before grabbing one for your kid.

Do I Need An Infant Car Seat? Are Convertible Car Seats Better? by Kevin Lu

What is the biggest infant car seat?

One of the largest infant car seats is Doona Infant Car Seat which comes with a LATCH anchor, head support, infant insert, vehicle seat protector, and a Doona Infant Car Seat Stroller.

What is the smallest infant car seat?

The smallest infant car seat is the Clek Foonf which measures 16.9 inches wide. Suppose you have a small vehicle; this would be a great purchase.

Can an Infant car seat be used as a part of the stroller?

Yes, some infant car seats can be used as part of strollers, such as Doona and Meta. All you need to do is confirm the infant car seat size and stroller measurements match for perfect fitting.

What are the biggest infant car seat manufacturers?

The biggest infant car seat manufacturers include Britax, Chicco, Graco, Maxi Cosi, Peg Perego, and Safety First. These companies offer the best infant and toddler car seats.

Conclusion

Every vehicle owner deserves the safest car seat for their infants, which can be challenging to find. But thanks to the Federal Motor Vehicle Safety Standard 213, it provides you with all the essential information. For instance, the correct angle, installation process, and crotch strap for your kid’s age.

With an infant-only seat size chart, you can secure the right infant car seat size for your toddler to provide maximum protection. Having any car seat concerns? Drop your question in the comments below, and we will have a professional help you sort it out!

Picture in this post is by Alexander Grey on Unsplash