Fit for a King, but a King Might Not Fit

Buying a too-small mattress is one of the biggest mistakes new bed-buyers make. Couples who’ve been sleeping on a “double” (also known as a full-size mattress) since they got together may think they have enough room – until they learn that each person has only as much sleeping space as a baby’s crib! This guide will help you understand mattress sizing, along with recommendations to find your best fit.

crib mattress size, Better Sleep Council


27" x 52"

In general, your baby’s crib mattress should be fairly firm. Soft mattresses and pillowtops seem like a good choice for parents, but infants need a solid sleep surface because they can’t move themselves out of positions where their face sinks into the mattress if they happen to flip over on their tummies. Push down on the mattress and see how easily your hand sinks. The more resistance, the firmer the mattress. Whether you choose an innerspring or solid foam mattress, just make sure it’s nice and firm! For more specific recommendations on babies and safe sleep see the American Academy of Pediatrics.
For many parents, the time to move their children into a bigger bed comes when they reach 35 inches in height or 2 years of age, whichever comes first. For that next bed, a twin mattress is a popular choice. For youngsters, consider using detachable safety rails to discourage climbing, prevent falls and help your toddler feel more secure. Another option is a full-size (also called a double) mattress that allows them freedom of movement while sleeping well into their teen years.
Twin mattress size, Better Sleep Council


38" x 75"

A twin (or “single”) mattress is the smallest possible mattress size other than a crib-size mattress. Twin mattress dimensions are approximately 38 inches wide by 75 inches long. At approximately 75 inches long, both twin and full mattresses may be too short for some adults.
A twin mattress is a good choice for children who have outgrown their cribs (see Crib Ideas). Twin mattresses can also be the perfect size for a guest bed, daybed or bunkbed, especially in smaller rooms.
Twin XL mattress size, Better Sleep Council

Twin XL

38" x 80"

A twin XL mattress is the same width as a regular twin (around 38 inches) but features an extra 5 inches length-wise (totaling 80 inches). They are around the same length as a king or queen mattress.
A twin XL might be a good alternative for those living in tight spaces. The XL offers several extra inches in length, but remains the same width as a regular twin. This extra length makes a twin XL a good option for taller children. It’s also a common size in college dormitories.
Full mattress size, Better Sleep Council


53" x 75"

Sometimes still called a double mattress, a full-size mattress is 53 inches wide, which is just 15 inches wider than a twin size (or “single”). For a couple sharing a bed, that leaves each partner only 27 inches of personal space — or about the width of a crib. Both twin and full sizes are approximately 75 inches long, which may be too short for some adults.
A full-size bed is really only enough space for a single sleeper and at only 27″ per person (the size of a crib), full mattresses are a tight fit for two. Plus, they’re the same length as a twin, which can be too short for many. Parents are increasingly choosing full sizes over twin sizes for teenagers’ bedrooms. Parents are even making this choice for younger children to give themselves a more comfortable place to sit or lie down when reading to children at tuck-in time and to avoid the child outgrowing the bed too quickly.
Full mattress size, Better Sleep Council


60" x 80"

Queen mattress dimensions are 60 inches wide by approximately 80 inches long – 7 inches wider and 5 inches longer than a full-size mattress. These added inches can make all the difference in comfort, especially for couples, and have made the queen-size mattress today’s most popular mattress size. However, with 30 inches of personal space, each adult still has 8 inches less width than if they slept alone in a twin bed.
A queen-size mattress is a good choice for couples who don’t need as much sleeping space or who want more living space in their bedroom. Single sleepers may also find they prefer plenty of space when snoozing, and the increased size of the queen over a full-size mattress makes for the ideal fit.
Full mattress size, Better Sleep Council


76" x 80"

The king-size mattress dimensions are 76 inches wide by approximately 80 inches long – about 16 inches wider than a queen. This is the closest a couple can come to having as much personal space (38 inches) as each would have on a twin bed. In fact, two twin extra-long beds pushed together are about the same size as a king, an option that can offer a flexible arrangement for a guest room.
A king-size mattress is the best choice for couples who want maximum personal sleeping space. To ensure that the king-size mattress will fit nicely into your bedroom, check your room dimensions. Also, think about how you’re going to move the mattress into your bedroom. For example, you’ll want to measure the corridors, doors and stairwells that the mattress will need to fit through. Alternatively, your delivery service, where applicable, may be able to advise you on moving your new king mattress into your bedroom.
Full mattress size, Better Sleep Council

California King

72" x 84"

Popular on the West Coast, a California king mattress is approximately 72 inches wide by 84 inches long – 4 inches narrower and 4 inches longer than a regular king.
For a large bedroom, or an especially long bedroom, the California king can help fill the space and give you plenty of room to catch some ZZZs. Just remember to get bedding to match the larger mattress size – regular king mattress sheet sets and other linens won’t fit properly. When measuring your bedroom, remember to take into account the size of a nightstand and whether you use one or two.