Twin XL Size: 38 x 80 Inches, How It Differs from Twin and Which Sheets Fit a Dorm Bed

A twin XL mattress measures 38 by 80 inches. That is the same width as a standard twin (38 by 75 inches) but five inches longer. Most US college dorm beds are twin XL, so students should buy twin XL fitted sheets. Standard twin fitted sheets are too short, and they pop off at the corners.

This article is part of our bed sizes chart, where you can compare related options.

Twin XL is the size that surprises people at the start of college. A student shops for bedding in a regular twin size, then discovers the dorm mattress is longer. Knowing the exact numbers saves a return trip.

The twin XL size is a mattress and bedding size that adds length without adding width. It suits tall sleepers, narrow rooms, adjustable bases and split king setups. This guide covers dimensions, how twin XL differs from twin, sheets and bedding, dorm tips and where else the size appears. Sheet dimensions vary by brand, so check the package.

Comfortable twin beds placed in front of TV set and bookshelf in contemporary bedroom with big windo

What are the dimensions of a twin XL mattress?

A twin XL mattress is 38 inches wide and 80 inches long. A standard twin is 38 by 75 inches. The Sleep Foundation’s dorm bed table lists both that way. Saatva, Tom’s Guide and National Mattress publish dimension guides that match. Thickness varies by mattress, so check the listing if you plan to buy sheets or a topper.

Our twin mattress dimensions guide explains the standard twin in more detail, and the king vs queen guide covers larger sizes.

How is twin XL different from twin?

The only difference is length. Twin XL is five inches longer, which is a big change for anyone taller than about 6 feet. Width stays the same, so both sizes fit narrow rooms. Mattress Firm and Mattress Store Los Angeles publish twin versus twin XL comparisons. Twin XL mattresses and frames cost a little more, and fewer stores stock them.

If you are tall, share a room or want room to stretch, twin XL gives that extra length.

Why do dorms use twin XL?

Most standard dorm beds at US colleges are twin XL at 38 by 80 inches, according to the Sleep Foundation’s dorm bed guide. The longer bed fits taller students. A small number of schools still use standard twin, and a few use non-standard lengths, so confirm with your housing office before buying sheets or a mattress topper. Turmerry and California Design Den publish dorm bed size guides.

Which sheets fit a twin XL bed?

Buy twin XL fitted sheets. Standard twin fitted sheets will not work on a dorm bed. They come up short and slip off at the corners. Sheet sizes vary slightly by brand: one seller says twin sheets are usually 39 inches wide and 75 inches long and twin XL sheets are 38 by 80, while others list a twin XL fitted sheet at 39 by 80. Check the package.

Flat sheets are more forgiving, because some manufacturers use the same size for twin and twin XL flat sheets. Our bed in a bag guide notes that dorm sets are often sold in twin XL.

What about comforters and toppers?

A twin comforter usually works on a twin XL bed because comforters are larger than the mattress, but check the drop. Mattress toppers must match the mattress, so buy twin XL. Our best cooling mattress topper and waterproof mattress protector guides explain toppers and protectors, and both should be sized for twin XL.

Who else uses twin XL?

Twin XL is common for adjustable bases, where two twin XL mattresses side by side form a split king. Our adjustable mattress guide covers this. It is also used for tall teens, narrow guest rooms and bunk or loft beds built for dorms. Folding mattresses in twin XL exist too, as our folding mattress guide notes.

What bed frames fit twin XL?

You need a frame made for twin XL, because standard twin frames are shorter. Many dorm beds come with the school’s frame, so you may only need a mattress and bedding. Check whether the school provides a mattress, since some do. If you buy a frame for home, confirm the slat length and weight rating.

How much room does a twin XL bed need?

The bed is only 38 inches wide, so it fits easily in a small room. Leave space to walk around it and to make the bed. In a dorm, the room layout is often fixed, so measure the space if you plan to add storage or a bed raiser.

What mistakes should you avoid?

The biggest mistake is buying standard twin sheets. The second is skipping the housing office check. The third is buying a mattress topper in the wrong size. The fourth is ignoring brand differences in sheet dimensions. Always read the package size.

What should you pack for a dorm with a twin XL bed?

Bring twin XL fitted sheets, a mattress protector in twin XL, a topper in twin XL and a comforter or duvet that covers the bed. A pillow, a spare pillowcase and a blanket complete the set. Check whether your school provides a mattress and whether bed risers are allowed. Our waterproof mattress protector, cotton sheets and linen bedding guides help with choices, and a bed in a bag set can cover the basics.

Is twin XL good for adults at home?

Yes, for single adults, tall sleepers and small bedrooms. It also suits guest rooms where two twin XL beds can sit side by side. If you sleep alone and want room to stretch, it is a good way to get extra length without a wide bed.

Frequently Asked Questions

What size is twin XL?

38 by 80 inches.

What is the difference between twin and twin XL?

Twin XL is five inches longer. Width is the same.

Do twin sheets fit twin XL?

Fitted sheets do not. Flat sheets may, depending on the brand.

What size bed do dorms use?

Most US dorm beds are twin XL, but confirm with your school.

Can two twin XL mattresses make a king?

Yes, as a split king. Check the base and sheet setup.

Conclusion

A twin XL bed is a twin that is five inches longer. For a dorm or a tall sleeper, buy twin XL fitted sheets, a twin XL topper and a twin XL protector.

Because some schools and brands differ, confirm the bed size and read package dimensions before you shop. That small check saves time and money.