A standard twin mattress measures 38 inches wide and 75 inches long, making it the smallest standard adult mattress size.
At first glance, twin and twin XL mattresses look nearly identical — but the length difference matters more than most people realize. Twin XL mattresses add 5 extra inches of length, making them 80 inches long and better suited for taller sleepers. For a complete overview of all mattress sizes, see our complete mattress size guide.
How Long Is a Twin Bed?
A standard twin bed is 75 inches long and 38 inches wide.
Twin mattress dimensions:
- 38" wide
- 75" long
Twin beds are commonly used for kids' rooms, guest rooms, bunk beds, and small bedrooms. Because they're compact, twin beds are ideal for tight spaces — but the 75-inch length may feel short for taller teens and adults.
How Long Is a Twin XL Bed?
A twin XL bed is 80 inches long, which makes it 5 inches longer than a standard twin.
Twin XL dimensions:
- 38" wide
- 80" long
That extra 5 inches is the same length as a queen or king mattress — just narrower. Twin XL beds are commonly used in college dorm rooms, adjustable bed systems, split king configurations, and taller teen bedrooms.
Twin vs Twin XL: Length Comparison
| Size | Width | Length |
|---|---|---|
| Twin | 38" | 75" |
| Twin XL | 38" | 80" |
The width stays the same. The length increases by 5 inches.
Who Should Choose a Twin?
A standard twin is best for children under 12, small guest rooms, daybeds, bunk beds, and very tight spaces. It's budget-friendly and widely available. If you're comparing twin to the next size up, see our full vs queen comparison.
Who Should Choose a Twin XL?
A twin XL is better for teenagers, adults under 6'2", college students, adjustable beds, and taller sleepers needing extra legroom. Many adjustable base systems are built around twin XL mattresses because two twin XLs together create a split king setup. See our adjustable bed buying guide for compatible base options.
Does Twin XL Bedding Fit a Twin?
No. Because twin XL is 5 inches longer, standard twin sheets will be too short. You must use twin XL sheets. See our bedding collection for compatible options.
Twin and Twin XL are our most popular hospital beds for home — and for good reason. Our popular home hospital beds (Hi-Low adjustable bases) come with free home installation and delivery — the perfect combination of comfort, accessibility, and space efficiency. See our adjustable beds for seniors guide for more on hi-low and accessibility features. Two twin XL Hi-Low bases can be paired together to create a split king setup, giving couples independent control. If hi-low functions are not needed, see our guide for sets under $2,000.
Mattress Options for Twin and Twin XL
Both sizes are available in all major mattress types. See our mattress type comparison to choose between memory foam, hybrid, and latex, and our mattress firmness guide to dial in the right feel.
FAQ
How long is a twin bed?
A twin bed is 75 inches long.
How long is a twin XL bed?
A twin XL bed is 80 inches long.
Is twin XL the same as extra long twin?
Yes. Twin XL and extra long twin are the same size (38" x 80").
Is twin XL longer than twin?
Yes. Twin XL is 5 inches longer than a standard twin.
Final Thoughts
The difference between twin and twin XL comes down to 5 inches of length — but that difference can dramatically improve comfort for taller sleepers. If you're shopping for a child's room, a standard twin is usually sufficient. If you're buying for a teen, college student, or adult, twin XL is often the smarter long-term choice. When in doubt, always consider the sleeper's height first — and see our complete mattress size guide for the full picture.
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