Twin Size (Single) Mattresses
From Kids Rooms to the Master Suite

Twin size beds have long provided an affordable and space-efficient choice for children, single adults, and guest rooms. And increasingly, they provide a more customizable sleep solution for master bedrooms.

Of the four traditional mattress sizes, twin-size mattresses have historically been used for children’s beds, day beds, bunk beds, and twin bed sets in guest rooms, but there’s more variety to the twin than many people realize. Most mattress brands and models come in twin sizes, although in luxury mattress lines, twin sizes can be harder to find or limited only to Twin XL.

Twin Size Mattress Dimensions

Here are a few variations on twin size mattresses (also known as "Single" size) that you may find:

Standard Twin

A twin-size bed, also known as a "single" bed, is the same length as a full-size bed, but is about 15 inches narrower — providing ample room for a single sleeper. Standard Twin mattresses measure 39” wide by 75” long. While suitable for all ages, this size is an especially popular choice with parents shopping for a youngster's first "big kid bed." A child as young as 2 or 3 years old can start on a twin-sized bed immediately after outgrowing their crib, although a guard rail for young children is advisable.

In most mattress lines, Twin is the smallest and least expensive option available.  A twin mattress typically costs 10-20% less than an equivalent full mattress.

Twin XL

Twin Extra Long (XL) mattresses, or “long beds,” were once found principally in college dorm rooms but their popularity has recently expanded far beyond that realm. One reason for this is that a pair of side-by-side TwinXL mattresses use the same footprint and furniture as a king-size mattress (more on this below). Extra long twin mattresses are the same width as the standard twin (39" wide) but are five inches longer, making them 80" long.

Super Single

Super Single mattresses are also sometimes classified as “twin," although they are actually somewhere between a twin and a full.  Super single beds are 9 inches wider than a twin (48" wide) with the same length as a California king mattress (84" long). This size is mostly limited to hard-side waterbeds.  As compared to the "3/4 bed" size, another less common size that falls in between twin and full, a super single is the same width, but is 9 inches longer.

Twin XL vs Twin – A Shifting Landscape

In recent years, Twin XL has gone from being a niche size found largely in special-purpose situations like college dorms to one of the three most commonly purchased sizes in some product lines. The reasons for this are due to its appeal with both adults shopping for themselves as well as parents shopping for their children.

The biggest driver of this shift has been the increasing adoption of Twin XL mattresses by adults shopping for their master bedroom. The appeal of Twin XL for this customer is that it's almost exactly half of a king-size mattress — meaning that when you place two Twin XL mattresses side by side, they take up the same space as a king-size mattress. With this setup, you can even use standard king-size furniture and bedding that you may already have. For this reason, Twin XL has even begun to replace Twin in many premium mattress lines.

What you gain with the side-by-side Twin XL approach is personalization. First, it allows each partner to select their own mattress — catering to their own personal comfort preferences and support needs rather than having to compromise on a mattress that isn't ideal for either partner. But just as important for some, having separate mattresses allows each one to be elevated independently of the other. So if you like to sit up late and read, your partner can still lie flat and go to sleep next to you. Or if your partner likes to fall asleep with their feet elevated, you can still sleep flat on your side. Naturally, this requires separate Twin XL adjustable bases under each mattress, but all of that can be done in the same space as a king-size bed. Not surprisingly, as the popularity of adjustable bases has skyrocketed since 2015, so has the popularity of Twin XL mattresses.

For parents, you may also have a reason to opt for Twin XL. Say you want the bed you choose for your child to have the opportunity to last through their teenage years, or even into young adulthood. Once kids grow beyond about 5'9" tall, a twin size mattress becomes a very tight fit, which is why colleges have long used Twin XL in their dorm rooms rather than a standard Twin. As such, the extra 5 inches of length in a Twin XL will give a mattress the potential to serve your family's needs longer into the future.

What Size is a Twin Bed in Canada?

A twin size bed in Canadian stores is the same size as a twin in the US, but you might see the measurements expressed in centimeters. So a twin-size mattress is 97 cm by 190 cm. A twin XL bed would measure 97 cm by 202 cm.

Single beds in the United Kingdom are slightly narrower, measuring 90 cm by 190 cm. Also available is an even narrower "small single," measuring 75 cm by 190 cm (about 30 inches wide).