Both are 38 in wide, but a Twin XL (80 in long) is five inches longer than a Twin (75 in). Those five inches are the whole difference, and they matter most for tall sleepers.
Twin: best for children and bunk beds, with the easiest bedding to find.
Twin XL: best for tall teens, adults, and college dorms; two make a split King.
Bedding is not interchangeable — a Twin XL needs the extra length.
A Twin and a Twin XL are the same width; the XL is longer. Both measure 38 inches wide. A Twin is 75 inches long, and a Twin XL is 80 inches long, five inches more. Those five inches are the whole difference. They give a Twin XL 3,040 square inches of surface to a Twin's 2,850 and, more usefully, enough length for a tall teenager or adult. Two Twin XLs placed side by side also equal a standard King, which is why they are the building block of a split King.
Feature | Twin | Twin XL |
Width | 38 inches | 38 inches |
Length | 75 inches | 80 inches |
Total surface area | 2,850 sq in | 3,040 sq in |
Best for | Children, bunk beds, smaller rooms | Tall teens and adults, dorm rooms, split Kings |
Minimum room size | About 7 x 10 feet | About 8 x 10 feet |
Also known as | Single | Twin Extra Long |
Twin size, in brief
A Twin is 38 by 75 inches, the smallest standard size. It is ideal for young children, bunk beds, and rooms that need to hold more than one bed. Its shorter 75-inch length is fine for children but can leave a tall sleeper's feet at the edge.
Twin XL, in brief
A Twin XL keeps the Twin's 38-inch width but adds five inches of length, reaching 80 inches, the same length as a Queen or King. That makes it a better fit for tall teens and adults as a single bed, which is why college dorms almost always use Twin XL. A pair of them side by side equals King dimensions, so they are also used to build split King and adjustable-base setups.
Which one should you choose?
For a child or a bunk bed, a Twin is the right size and easier to find bedding for. For a tall teenager, an adult in a single bed, or a dorm room, choose the Twin XL for the extra length. If you are building a King out of two mattresses for an adjustable base or differing firmness, you need two Twin XLs, not two Twins.
Twin and Twin XL at Avocado
Avocado offers both Twin and Twin XL across its line of certified organic mattresses, built with the same materials and support system. A pair of Twin XLs also works with our adjustable bases to build a split King.
Frequently asked questions
What is the difference between a Twin and a Twin XL?
Length. Both are 38 inches wide; a Twin is 75 inches long, and a Twin XL is 80 inches, five inches longer.
Is a Twin XL good for adults?
Yes, better than a Twin. Its 80-inch length matches a Queen or King, so it fits tall adults, while its 38-inch width suits a single sleeper.
Why do dorms use Twin XL?
The extra length fits taller students, and the narrow width fits small rooms, so most colleges standardize on Twin XL.
Do two Twin XLs make a King?
Yes. Two Twin XL mattresses side by side measure 76 by 80 inches, the same as a standard King, which is how a split King is built.
Can I use Twin sheets on a Twin XL?
No. A Twin XL needs sheets cut for the extra five inches of length; standard Twin sheets will not fit properly.
Is a Twin XL wider than a Twin?
No. They are the same width, 38 inches. Only the length differs.
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