Updated September 18, 2021When it comes to beds, two popular sizes are full and double mattresses. However, they’re actually the exact same size, both measuring 54 by 75 inches.Double mattresses were one of the first standardized mattress sizes along with single beds, meaning they’re a universal bed size amongst mattress manufacturers. As mattress manufacturers began adding more standard mattress sizes—like queen and king beds—they started calling single and double beds twin and full beds instead.What is a Full Mattress?Full size mattresses measure 54 inches wide by 75 inches long. Compared to other standard mattress sizes, full beds are a median size, not being too big or too small.If you want a new mattress, we suggest making sure your room is no smaller than 10 by 10 feet to accommodate the dimensions of a full size bed. This way, you have enough room for the mattress, its foundation or bed frame, and any other furniture in the room, all while still having space to walk around.What is a Double Mattress?The double bed size measures 54 inches wide and 75 inches long, so it has the same dimensions as a full mattress.In the early 1900s, mattress manufacturers started standardizing mattress sizes and, at the time, only offered two sizes: single and double. The term double seemingly suggests that it’s twice the size of a single bed. However, this isn’t true. While double and single mattresses are both 75 inches long, double size beds are only about a foot wider than single beds.Single (also called twin) mattresses were designed for single sleepers, while double mattresses were designed for couples. Between the 1940s and 1950s, manufacturers realized double mattresses were getting a bit too small for two people—the average adult was taller and weighed more than those in the 1800s—and instead started offering king mattresses and queen mattresses for couples since they offered extra length.Today, the term “double” mattress is uncommon, especially for mattresses made in the United States. However, mattress companies throughout Europe still occasionally refer to 54 by 75 inch mattresses as “doubles.”Who Should Use a Full or Double Mattress?While commonly available, full and double mattresses aren’t always the popular choice for everyone. The groups of people we recommend to get a full or double mattress include children and teenagers, young adults, and people with smaller bedrooms.Children and TeensFull and double mattresses are a good fit for older children and teens. Unlike a toddler bed or twin size mattress, full and double beds are big enough for a child to grow into comfortably so it’ll last them well into their teen years. At the same time, most teenagers aren’t large enough to need a bed bigger than a queen, especially if they’re less than 6 feet tall.SEE ALSO: Best Mattress for Kids (2021): Reviews and Buyer’s GuideSingle AdultsIf you’re a single person shorter than 6 feet tall, double and full size beds might be the best mattress for you. They’re bigger than twin mattresses—so you’ll have plenty of room to stretch out—but are more affordable than queen size beds—so you don’t have to worry about breaking the bank.People With Smaller RoomsIf you only have a small room to work with but still want to maximize your sleeping space, a full or double mattress might be a good choice for you. Whether you need a bed for a guest room or children’s room, be sure the room is at least 10 by 10 feet so there’s enough space for the bed and any other furniture.Especially as an adult, it’s normal not to want a small bed like a twin or twin XL size mattress. However, a queen bed may be too large for small bedrooms. When you’re working with limited space, a full or double mattress may work best.Similar Mattress Size OptionsWhile full and double mattresses have a lot to offer, there are other standard sizes available for mattresses that may work better. Some other options worth considering include full and double XL, queen, king, and California king mattresses.Full XL and Double XLSimilar to a twin XL mattress, full XL and double XL mattresses are just like they sound—larger versions of full and double mattresses. Double and full XL mattresses are the same width as traditional double and full beds but are 5 inches longer, so they measure 54 by 80 inches.You may prefer a full or double XL mattress if you’re a tall sleeper, but either don’t have the budget or space to accommodate a queen or king size bed. Despite the extra height, full XL and double XL beds still aren’t large enough to accommodate two sleepers.The drawback of a full XL mattress is that it’s not a common size. You may need to browse online mattresses if you’re interested.QueenThe dimensions of queen mattresses measure 60 inches wide by 80 inches long. They’re the smallest mattress size we recommend for couples, but are also a great option for single sleepers.While queen size mattresses are a standard size, some lesser-known variations of queen beds include the short queen, Olympic queen, and split queen.SEE ALSO: Full vs. Queen Mattress: What’s the Difference?KingKing size mattresses are the largest standard mattress size and one of the best for couples. They’re 76 inches wide and 80 inches long, which provides lots of surface area for two people to stretch out and sleep comfortably.A common variation of the standard king mattress is the split king size mattress. They’re designed for couples who either want a split adjustable bed base or have different firmness preferences. Each mattress on a split king is equivalent to a twin XL size mattress.Rarer variations of king mattresses include the Wyoming king, Texas king, and Alaskan king beds.SEE ALSO: King vs. Full: What’s the Difference?California KingWhile many people assume California king size mattresses are larger than king mattresses, they’re actually slightly smaller. A California king mattress is 72 inches wide and 84 inches long, making it 4 inches narrower and 4 inches longer than a king size mattress. They’re intended for taller people or couples who aren’t comfortable on shorter beds.A California king mattress may also be referred to as a Western king, similar to how full and double are different names for the same bed. Similarly, a regular king mattress may also be called an Eastern king bed.SEE ALSO: King vs. California King: What’s the Difference?FAQsDo full and double mattresses have the same dimensions?Yes! Both full and double mattresses are 54 inches wide and 75 inches long. The primary difference between the two mattresses is their name, thus why they share the same dimensions. If you have a double mattress, full size accessories are compatible with it and vice versa.Is a double bed the same as a twin bed?No, double beds are 16 inches wider than twin beds, which makes a massive difference in terms of your sleep surface and overall comfort.Twin beds are 38 inches wide and 75 inches long, making them a good option for toddlers, children, teens, and single adults. A regular twin bed fits inside trundle beds, bunk beds, daybeds, and other space-saving frames if you’re looking to maximize your living room.Can two adults sleep on a full mattress?Adults should avoid sharing a full mattress since each person would only get 27 inches of width to themselves, which is thinner than an infant’s crib mattress! Such a narrow bed would be uncomfortable for two people long-term.It’s best to get a queen size mattress or larger if you share a bed so both people have extra width to themselves. Plus, queen mattresses even suit smaller master bedrooms, so you won’t have to worry about room size as much with this bed size.Are double beds too short for adults?Double beds can be great for adults depending on their body type and how tall they are. If you’re shorter than 6 feet tall, then a double bed should be comfortable for you. However, if you’re over 6 feet tall, then your feet will likely stick out over the edges of your bed or bump the footboard.How do you know if you need a bigger bed?Choosing a mattress size may come to personal preference and budget, but a very clear sign that you need a larger mattress is that you’re uncomfortable in it. Whether you share a bed or not, smaller sizes could mean you don’t have the space to stretch out, your feet hang over the end of the bed, or you can’t switch positions easily.Do you share a bed? You may notice you and your partner bumping into each other constantly, struggling to share the blankets, and unable to get into a comfortable position due to the lack of space. If you’re over 6 feet tall, consider standard twin XL, full XL, king, split king, or California king beds because they are all over 80 inches long.ConclusionSince full and double beds are the same size, it’s perfectly fine to use the terms interchangeably.Most mattress salespeople—regardless of if you’re speaking in-person or over an online chat box—will know what you’re referring to whether you call the beds a full or a double. Similarly, accessories such as bedding sets for full and double mattresses are the same, so there’s no need to worry about whether a double mattress sheet set will fit on your full size mattress.About the author Kiera PritchardKiera Pritchard’s curiosity around dreams and dreaming sparked her passion for sleep science. In addition to freelancing for eachnight, Kiera is also a physical trainer and strives to help others lead healthy lives while asleep and awake. Since joining our team, Kiera has compiled multiple sleep health guides offering our readers advice on how to improve their days and evenings. Find more articles by Kiera Comments Cancel replyLeave a CommentYour email address will not be published. Required fields are marked * Comment Name Email I agree to the Terms and Conditions of this website.