Single vs. Twin Bed: What’s the Difference?

October 7, 2021 | Casper Editorial Team

With so many mattress sizes to choose from, it’s no easy feat to determine which is right for your needs. If you’re a single sleeper looking for a space-efficient mattress, you’ve likely come across the terms “single” and “twin” bed. But what’s the difference between a single vs. twin?

In short, single and twin are the same thing. Both mattresses are 38 inches by 75 inches and are designed for single sleepers and small spaces.

Want to learn more about single and twin beds? Keep reading to learn the history of the two bunk bed-sized mattresses.

Our innovative twin size mattresses are the perfect combination of support, cooling, and comfort. They’re squeezed into a tiny box, which is magically delivered to your doorstep within a few days. 

Single vs. Twin Bed: What’s the Difference?

The terms “twin” and “single” both refer to the same bed size. Both a twin and single bed are 38 inches wide and 75 inches long. While the terms are often used interchangeably, twin has become the more popular way to refer to this specific bed size. 

Here are some fast facts explaining how the twin bed got its name:

  • After the Civil War, mattress manufacturers predominantly made two bed sizes: single (twin) and double (full). 
  • The term originated from hotels that used to place two single beds together to make a double.
  • While you may think that the name “double” suggests that a double mattress is twice as wide as a single — and hey, who could blame you? — double mattresses are actually only 16 inches wider than a single.
  • Eventually, people switched to the arguably more logical terms “twin” and “full” — with twin referring to a single mattress and full referring to a double

Although the terms “single” and “twin” are somewhat interchangeable, twin is more common nowadays.

Single and Twin Bed Dimensions 

Here are some quick figures on single vs. twin bed dimensions:

  • Single mattress width: 35”
  • Single mattress length: 75”
  • Single mattress size: 38” x 75” or 2,850 square inches

Did you know that some twin beds can be put together to make a bed that’s almost the exact size of a king? However, to make a true king bed, you’d need two twin XL mattresses, which measure 38 inches by 80 inches. Check out some more fun size comparisons below:

How To Choose Your Mattress Size

Whether you’re looking for a space-saving twin or more room to sprawl, check out these important factors to consider when choosing your mattress size.

Factor #1: Your Height

Since twin mattresses are 75 inches long, taller sleepers may prefer the extra 5 inches of a twin XL mattress. Here’s a basic breakdown of the various mattress heights:

  • Twin mattress height: 6’3”, suitable for sleepers with a height of under 6 feet 
  • Twin XL mattress height: 6’8”, suitable for most sleeper heights

When you factor in the additional length added by your pillows (a standard pillow is 18 inches by 26 inches), taller sleepers may find their feet hanging off the end of a regular twin mattress.

Factor #2: Cost

If cost is your primary concern, you’ll love the cozy prices of twin and twin XL mattresses. Our most affordable mattress, The Casper, starts at $595 for a twin and $695 for a twin XL, while our most luxurious line, the Wave Hybrid, starts at $2,395 for a twin XL. 

If you want to meet in the middle, check out our most popular, the Original Hybrid mattress, for the just-right price of $1095 for a twin and $1195 for a twin XL. 

Factor #3: Room Size

If you’re a single sleeper with limited bedroom real estate, a twin bed may be the wiser choice. Generally, twin beds are recommended for rooms as small as 7 by 9 feet. If you have other furniture such as a dresser, desk, or bedside table, a twin bed may be a good choice.

However, you should remember that everything is relative. Some people with small bedrooms will opt for a larger full size bed that touches three walls — this is particularly common in large cities with small apartment sizes. As long as your mattress fits within your room dimensions, we say do what’s coziest for you!

Factor #4: Thickness

Most mattresses range in thickness from 9 to 12 inches. We’ve found the bed height sweet spot to be 11 inches for that perfect balance of support and plushness. 

When choosing your preferred mattress thickness, it’s important to know that thicker isn’t always better. If you choose a too-thick mattress and add a mattress topper, you may struggle to find sheets that fit your custom bed dimensions. Luckily, Casper sheets are designed with a depth of 18 inches, making them compatible with most bed heights and mattress toppers. 

Factor #5: Composition

One of the most important factors in choosing a mattress is composition, which is the materials the mattress is made of.

Do you prefer the support of memory foam or the responsiveness of a hybrid? For those who prefer a softer feel, you may want to opt for a memory foam mattress, while those who enjoy firm responsiveness may favor a traditional innerspring mattress.

Check out our guide to the different types of mattresses for a full breakdown or take a look at the image below for a quick view.

Factor #6: Compatibility

When choosing your mattress, you’ll also want to think about the accessories that go along with it. Are you getting a custom headboard? What about a body pillow?

Many headboards are designed for larger bed sizes, like queen and king beds. If you love the look of a headboard but want a twin bed, check out our bed frames to find your perfect fit.

Finding your perfect mattress match is not an easy task (say that five times fast!). You’ll want to consider factors such as room size, your height, and the amount of money you want to spend. 

Want to compare other popular mattress sizes? Check out our mattress size comparisons below so you can make an informed decision about what bed size is right for you:

Ready for a great night’s sleep? We have four unique mattress lines, so you can find the perfect bed for your needs. And if you don’t, just return it within 100 days and try again — on the house.