The Britax Marathon Convertible Car Seat is designed with security, durability and functionality in mind. With the safety of your baby as the number one priority, the car seat delivers tested safety mechanisms as well as comfort, ease of use, and quality build.

Britax has been providing child safety technology since its launch more than 70 years ago in Europe. The company continues to explore and develop new technologies aimed at overcoming mobility challenges that affect the daily lives of families.

Top Features of the Britax Marathon Convertible Car Seat

The Marathon Convertible Car Seat is made with high quality materials and designed in the USA. It has the following key features: impact protection, ease of use, overall comfort, and functional appearance.

Ultimate Impact Protection
The Britax Marathon Convertible Car Seat comes with an impact-absorbing base, stabilizing integrated steel frame, patented v-shaped tether, and unmatched side impact protection. These help ensure the child’s utmost safety and the least possible effect to them in case of collision.

The deep energy-absorbing shell of this convertible car seat provides side impact protection which works to secure your child in the seat especially during a collision. The impact-absorbing harness provides strong resistance to forward movement, minimizing impact that could cause head injury, and keeping your child’s chest clip in place.

The car seat is also designed with a proactive SafeCell Impact-Absorbing Base that boasts of energy absorbing expanded polypropylene (EPP) foam. The compressible structure of the base and the EPP foam divert the energy from a collision away from the seated baby, reducing the force of the impact on your child.

Meanwhile, the integrated steel frame of the Britax Marathon Convertible Car Seat also adds greater stability and strength. It helps secure the car seat to the vehicle and thus reduces the seat from moving forward during a crash. 

Another point of impact protection is the patented V-shaped tether of the car seat. The uniquely-designed tether features a 2-point attachment that minimizes seat rotation and reduces the force of impact on your baby in case of a sudden stop.

Ease of Use Right from Installation

From installing the seat to ensuring the proper fit, the Britax Marathon Convertible Car Seat has built-in mechanisms for your ease of use and convenience.

The build-in lock-offs for seat belt installation that come with the car seat can guarantee tight and snug seat belt installation with minimal effort. The car seat also comes with simple and secure LATCH connectors that can be locked into place with an audible click. Another push of the button easily releases the LATCH connectors.

The seat of the Britax Marathon can also be easily adjusted to accommodate installation and child use. It comes with three recline positions that can be angled for the proper fit. As you place your child in the car seat, the easy-buckle system also keeps the buckle out of the way.

Overall Comfort Assures a Happier Ride for Your Little One

Several features of the Britax Marathon Convertible Car Seat provide overall comfort, even as your baby is growing up and going through changes in height and weight.

The 10-position Quick-Adjust Harness and the 2-Position Buckle can ensure that the child is comfortable and secure, with no re-threading needed. The harness ultra-guard system (HUGS) offers forward resistance, making it essential in case of a crash.

For maximum comfort, the seat is outfitted with plush foam padding and smooth fabrics which are perfect for kids’ often sensitive skin. There is also a removable body pillow for a cozier feel.

Simplified Appearance that Complements Functionality

Offering a simple and intuitive design, the Britax Marathon comes in several colors and designs, including static, azul, confetti and kiwi.

With the easy-remove cover, cleaning and maintenance is easy and hassle-free.
Britax Marathon Specs

This convertible car seat weighs only 19.5 lbs., and has product dimensions of 18.5” W x 26” H x 21” D. This makes the seat easy to carry around from place to place. The seat area depth is 11” and the width is 11”. The car seat shoulder width is 13”. The harness slot heights vary from 8.5” to 17.5”, and the buckle strap depths are 5” and 7.5”.

The Britax Marathon car seat can accommodate children that weigh between 5 and 40 lbs. when rear facing, and between 20 and 65 lbs. when forward facing. The maximum child standing height recommended is 49”. When seated, the child shoulder height should be from 9 to 16.75 inches when rear facing and from 12 to 16.75 inches when forward facing).


The Britax Marathon Convertible Car Seat assures top quality, without a doubt. The design, testing and manufacturing of the car seat were all done in the USA. As such, it comes as no surprise that Britax has already bagged a number of awards for this product, including BabyCenter Moms' Pick in 2014, SafeWise Recommended in 2016, and BabyGearLab Editor's Choice also in 2016.

This convertible car seat is a good option for parents who believe that a high quality child’s car seat is a great investment. To provide your child not only safety and comfort but also lots of fun while sitting pretty in your car, you might also want to add Britax accessories like a convertible child cup holder, EZ buckle belly pad, or EZ –Cling Window Shades.