Learn about mattress sizes and dimensions

Also known as “single” mattresses, twin mattresses measure 39 inches by 75 inches and fit one child or adult sleeper. Twin beds save space and comfortably accommodate growing children, but many adults and taller adolescents find that the limited space they offer isn’t enough. If you’re shopping for a daybed or bunk beds, most are designed to fit with standard twin mattresses, and a twin’s economical size suits it well to small or oddly shaped bedrooms. Though not the standard size for a dorm room mattress, a twin mattress is both economical and easy to move, so it also works well for less permanent living situations.

A hallmark of college dorms everywhere, the Twin XL mattress provides 39 inches of width and 80 inches in length to students and growing adolescents. Its economical cost and practical size make it a popular choice for taller sleepers looking to save space without sacrificing sleep quality with a twin. While bunk beds and daybeds are more commonly made for standard twin mattresses, a Twin XL is still a great choice when outfitting a small guest room, a shared kids’ bedroom, or of course, a college dorm room. Far easier to maneuver than larger sizes, a Twin XL might continue to serve your college student after graduation.

Measuring 54 inches by 75 inches, a full size mattress offers sleepers a noticeable fifteen inches of additional width compared to a twin bed. Adults and growing kids will have more space to stretch out and move around at night with the extra inches, but the full mattress is still best for single sleepers. Though a lower price tag and added space may be tempting for couples, sharing a full bed with another person gives each sleeper only a crib’s width of space, which isn’t ideal. For larger bedrooms, first apartments, and teens who have outgrown their bunk beds, a full mattress represents an excellent upgrade.

The queen mattress is the most popular mattress size in the US right now, and its dimensions—60 inches by 80 inches —give both singles and couples alike the space they need to sleep comfortably. Most standard bedrooms and doorways can accommodate a queen mattress without compromising walking space, and queen mattresses are more affordable than king mattresses and beds in specialty sizes. These factors, as well as the wide availability of queen mattresses, accessories, and bedding, make the queen bed a versatile choice that many sleepers feel grows with them through moves and other life changes.

With generous dimensions of 76 inches of width by 80 inches in length, king size mattresses give couples a luxurious amount of individual sleeping room. If you and your partner share your space with young children or pets on occasion and don’t want to compromise space, a king size mattress is the best choice, and will give you each the same amount of room you’d have on a twin XL mattress. Unlike some specialty mattress sizes, king size mattresses are widely available, so they’re easy to outfit with accessories like split boxsprings (for narrow staircases), headboards, and sheets.

For taller sleepers who crave space to stretch out each night, the California king mattress provides 72 inches of width and an expansive 84 inches of length to individuals and couples. Four inches slimmer than a conventional king mattress, a Cal king may be easier to accommodate in certain bedrooms, but it still gives couples almost the equivalent individual space of a twin XL mattress. If you’re looking for the right mattress for an adjustable bed, a California king is an ideal choice. You’ll barely notice the slimmer width compared to a traditional king, and you won’t have to sacrifice length when your head or feet are elevated.