Description
The standard length of a marathon is 26.2 miles, and the Britax Marathon Convertible Car Seat will cover more than 100 times that distance.
The Britax Marathon Convertible car seat is one of the most functional seats to ever hit the market. Slightly larger than other Britax Car Seats, the Marathon is legendary for safety and comfort. It's important to note that the shell of the car seat is a bit bulkier than others, so parents should allow for about 31 inches of seat space when used rear facing.
Some of the unique features on the Britax Marathon Convertible Car Seat include a five-point polyester harness with no-tangle polyester webbing, built in lock-offs for the car’s seat belts, and a push-button LATCH system with VersaTether. This Britax Car Seat provides the utmost security in both forward and rear facing installations. The Britax Marathon has Expanded PolyStyrene (EPS) padding to protect your baby in the event of a collision. Britax convertible car seats are equipped with their patented HUGS system, which is designed to better distribute webbing loads to reduce head movement and minimize the chance for the webbing's edge to load on the child’s neck.
The Britax Marathon provides parents with an all around top-rated car seat. However, it might be too large for compact cars. For those looking for a smaller Britax Car Seat, the Britax Roundabout is a perfect choice. It is a little smaller than the Britax Marathon, and it is designed for children weighing up to 40 pounds.
Product Features
- LATCH equipped
- Expanded PolyStyrene (EPS) foam insert to increase available shoulder width room
- HUGS System is designed to better distribute webbing loads to reduce head movement and minimize the chance of injury
- Built in Lock-Offs, both forward facing and rear facing, are designed for easy reach and operation when using traditional belt routing
- Britax Marathon Convertible Car Seat has a Five-Point Polyester Harness for a secure fit
- Four different shoulder harness positions will accommodate the taller child and are easy to adjust
- Use vehicle seat belt (not LATCH connectors) for installations with children weighing more than 48 pounds
- One-hand recline adjustment
- Velcro belt holders keep belts aside while boarding
- Britax Marathon has a sculpted base for a perfect fit
- Belly pad for added comfort and protection
- Approved for aircraft use and conforms to all applicable federal Motor Vehicle Standards
- LATCH connectors are stored under the fabric on either side and should be inserted with the rounded side up
- Product manual is tucked under the fabric of the seat
- Fabric is removable and hand washable
- Rear facing for children weighing 5 to 35 pounds
- Forward facing for children weighing 34 to 65 pounds
- Maximum child height of 49 inches
- Product Dimensions: 28 inches high x 19.5 wide x 25 deep
- Interior Seat Dimensions: 11D x 11W x 23.5H inches
- Seat weight: 17.5 pounds
This product is available in other styles
Reviews

Love it!!!
- Danielle Smith I purchased two of the marathons for my 2 and 3 three year old at the time.
I've tried Graco and evenflo in the past and was not happy, mainly for comfort and their heads flopping forward, when they fell asleep.
I heard about the Britax carseats and my husband and I decided to try them out. My boys love them, even my oldest daughter wanted one for herself. Their heads don't flop forward and they don't complain when riding in them.
My boys are now 4 and 3 and still love their seats. I know they are not cheap, but when it comes to the safety of your child, cost does not matter.

Britax
- J. Reed I was in a car accident where I reached back to give my kid somthing and my car swirved over to the other lane. Needless to say, the accident was horrendous, when I looked back at my son in his Britax, he was playing with his toys, he never even notice the accident and the car seat was in tack! I had to buy a new car seat and doubt about it I purchased the Britax. I also was urgin people to purchase the car seats.
Thanks Britax!

Britax Marathon
- Cassie This is a great car seat. It fit both backwards and forward facing in my Honda Civic.
It is esay to wash and I do dry the cover even though they say not to. The only concern I have is that my son is tall, so he already is at the top harness slot and is only 40lbs. I would assume he will out grow this car seat before he reaches 65lbs. Well worth the money for me and I will be buying the Britax booster seat next.

Love the Marathon!
- Danielle My son is big for his age, so we thought we’d better go with the Britax Marathon. He was 35 pounds when we got it and we thought it would last for awhile. We started out with it rear facing, and I love the fact that we could switch it to front facing as he got heavier. The harness straps were also super easy to adjust as he got taller (he grows at an incredible rate!). The safety features on the Marathon are top notch. I would not take my baby anywhere without a car seat with side impact protection. Tyler finds the Marathon seat really comfy and he likes to recline in it. Love the belly pad! It’s great that I can remove the fabric and wash it, and I bought additional covers too.