How does the boulevard compare with marathon car seat in terms of size?

Hi Danuta, thank you for your enquiry, the max shoulder height for the Marathon is 43cm & 47.3cm for the Boulevard, this is about the only difference with height & weight. We hope this helps. ?For further information on this or any of our other products available, if you follow the link https://www.babyonthemove.co.nz/store-locations/ this will take you to our online store finder. Here you can find contact details for your nearest Baby On The Move Store where one of our team experts will be happy to assist you in your product search and help answer any further questions you may have. We hope this has helped with your query.