Twin size beds provide an affordable and space-efficient choice for children, single adults, and guest rooms.
Twin is the smallest and least expensive size of the four traditional mattress sizes. 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. A twin mattress typically costs 10-20% less than an equivalent full mattress.
Twin mattresses are typically 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 a twin size may be difficult to find for the most high-end luxury mattresses.
Standard Twin mattresses measure 39” wide by 75” long. They’re suitable for kids of all ages, and a child as young as 2 or 3 years old can start on a twin-sized bed immediately after a crib, although a guard rail for young children is advisable; if you go this route, the bed you choose for your toddler could last through the teenage years.
Twin Extra Long mattresses are often found in “long beds” in college dorm rooms. Extra long twin mattresses are the same width as the standard twin (39" wide) but are five inches longer (making them 80" long). As such, you may have to buy new sheets for your college student.
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.