Twin vs Twin XL Mattress: Size Differences and Which to Choose

A twin mattress measures 38 x 75 inches and a twin XL measures 38 x 80 inches, so the only difference is that the twin XL is 5 inches longer. Choose a twin for kids and sleepers under about 6 feet tall, and a twin XL for taller teens, taller adults, or a future split king.

Twin vs Twin XL Size Chart

A twin and a twin XL share the same 38-inch width, and the twin XL adds 5 inches (13 cm) of length, as this chart shows.

Those 5 inches add about 7 percent more sleeping surface. Because the width does not change, a twin XL needs no more wall space than a twin, only a little more floor from head to foot. For every other standard size, see the mattress sizes and dimensions chart.

What Is a Twin Bed?

A twin bed is the smallest standard adult mattress size, 38 inches wide by 75 inches long, made for one sleeper. It is also called a single bed, and both names describe the same size.

Twins are a staple of kids’ rooms, bunk beds, trundles, daybeds, studio apartments, and guest rooms that hold more than one bed. A twin also makes a practical first big-kid bed, since it spares parents from buying a toddler bed that sees only a couple of years of use. When you are ready to shop, start with the best twin size mattresses, or see the best mattresses for guest rooms if the bed is for visitors.

The main limit is length. Sleepers over about 6 feet tall may find their feet reach the edge of a twin, especially once a pillow takes up room at the head of the bed.

What Is a Twin XL Bed?

A twin XL bed is a twin with 5 extra inches of length, measuring 38 inches wide by 80 inches long. That extra length is usually enough for sleepers about 6 feet tall or taller who still want a narrow, one-person bed.

Twin XL is also a common size in college dorms. The University of Minnesota housing guide notes that twin XL beds are standard in many college residence halls, so buy twin XL bedding for school unless the housing office lists a different size. The size also suits adults in small bedrooms and guest rooms that host taller visitors.

Compare options in the best twin XL mattresses. If you are close to 6 feet 8 inches tall, even a twin XL can feel short, and the longest standard size is the California king, at 84 inches.

How Much Room Do You Need for a Twin or Twin XL?

A twin fits in a room as small as about 7 x 8 feet and a twin XL in about 7 x 9 feet, assuming roughly 2 feet of walking space on the three open sides of the bed.

These are comfortable minimums, not hard rules. Pushing a bed against a wall frees up floor space, and a bunk bed fits two sleepers in the footprint of one bed.

Sheets, Frames, and Bedding for Each Size

Twin and twin XL fitted sheets and bed frames are not interchangeable, because the 5-inch length gap is enough to throw off the fit. A twin fitted sheet is usually too short to reach all four corners of a twin XL, and a twin XL fitted sheet tends to bunch and slip on a shorter twin.

Flat sheets, blankets, and comforters are more forgiving, since they drape over the mattress instead of gripping it. A twin flat sheet on a twin XL simply leaves less fabric to tuck at the foot. Some sheet sets are labeled to fit both sizes, so check the package before you buy.

Frames need an exact match. A twin XL mattress will not sit properly on a twin frame, and a twin mattress on a twin XL frame leaves a 5-inch gap. The same goes for mattress toppers and bunk beds: buy the size the frame or mattress was built for.

Can Two Twin XL Mattresses Make a King?

Yes, two twin XL mattresses side by side make a split king, which measures 76 x 80 inches, the same size as a standard king. Two regular twins do not work, because together they measure 76 x 75 inches, 5 inches shorter than a king.

A split king lets each partner choose a different mattress or firmness, and it pairs with split adjustable bases that raise each side on its own. If that setup appeals to you, see the best split king mattresses.

What Firmness Works Best on a Twin or Twin XL?

The right firmness depends on your sleeping position and body weight, not on whether you choose a twin or a twin XL. On the Sleep Junkie firmness scale, where 1 is softest and 10 is firmest, these ranges are the place to start:

• Side sleepers: medium-soft to medium, 3 to 6. See the best mattresses for side sleepers.
• Back sleepers: medium to medium-firm, 5 to 8. See the best mattresses for back sleepers.
• Stomach sleepers: medium-firm to firm, 7 to 10. See the best mattresses for stomach sleepers.
• Combination sleepers: medium to medium-firm, 5 to 8. See the best mattresses for combination sleepers.

These ranges assume a sleeper of about 130 to 230 pounds. If you weigh under 130 pounds, go one step softer, and if you weigh over 230 pounds, go one step firmer. Lying on my side, I pay attention to pressure at the shoulder and hip, since those are the spots where a surface that is too firm tends to push back hardest.

Which Should You Choose?

Pick a twin or twin XL mainly by height, then by room size, budget, and bedding plans.

Choose a twin if:

• You or your child is under about 6 feet tall.
• The room is small or has to fit two beds.
• You want the lowest price, since a twin is usually the cheapest size of any mattress model.
• You move often and want the easiest size to carry up stairs and around corners.

Choose a twin XL if:

• You are about 6 feet tall or taller, or you are buying for a teen who may keep growing.
• You want a bed that takes the same sheets as many college dorm beds.
• You may want to pair two mattresses into a split king later.

Both twin sizes are one-person beds, so if 38 inches feels narrow for how much you move, a full adds 16 inches of width; the guides to twin vs full and twin XL vs full compare those trade-offs. Couples should skip both twin sizes and start with the best queen size mattresses.

Bottom Line

A twin XL is a twin with 5 extra inches of length, so height usually decides it: a twin suits kids and sleepers under about 6 feet, while a twin XL suits taller sleepers and dorm-bound students. Once you have picked a length, the guide to how to choose a mattress walks through type and feel. For a medium-feel pick offered in both sizes, consider the Amerisleep AS3.

Frequently Asked Questions

Can you use twin sheets on a twin XL bed?

You can use a twin flat sheet on a twin XL, but a twin fitted sheet is usually too short to stay on all four corners. The twin XL is 5 inches longer, so the elastic tends to pop off at the foot. Look for fitted sheets labeled twin XL, or a set marked to fit both sizes.

Which is better for bunk beds, a twin or a twin XL?

The better choice is whichever size the bunk bed frame was built for, because the mattress has to match the frame. Standard twin bunks work well for younger kids, while twin XL bunks give teens and taller guests more legroom. Before you buy, check the frame’s listed maximum mattress thickness as well.

Will a teenager outgrow a twin XL?

Unless a teen grows exceptionally tall, a twin XL should keep fitting through the teen years and beyond. At 80 inches long, about 6 feet 8 inches, it leaves room for sleepers several inches over 6 feet. A teen who is already close to that length would need a longer bed.

Is a twin or twin XL better for an adult?

A twin XL is usually better for adults about 6 feet tall or taller, while a twin works for shorter adults who need to save space. Height is not the only factor: both sizes are 38 inches wide, so adults who sprawl, share a bed, or sleep with a pet may be happier on a full or larger size.

How much more does a twin XL cost than a twin?

A twin XL usually costs a little more than the same mattress in a twin, and both sizes are among the least expensive in any lineup. The mattress type matters more than the size: hybrid and latex models tend to cost more than innerspring and all-foam ones, so either size can run from a couple of hundred dollars to over a thousand.