Some RVs may require custom mattresses. RVs have various bed sizes, depending on whether it’s designed for a family or one couple. If it sleeps multiple people, it probably has RV bunk mattresses, which range from 28 inches wide and 75 inches long to 35 inches wide and 78 inches long. If the RV sleeps only one couple, it may have a short king (72 inches by 75 inches) or a short queen (60 inches by 75 inches), both smaller than their standard sizes.
Most RVs come with mattresses that fit each bed, but they are usually made of 5-6 inches of foam and not very comfortable. To get your best sleep while traveling, you should consider ordering a custom mattress that fits your RV bed and suits your sleep needs.