Twin vs. Full: Mattress Size and Comparison Guide

May 24, 2022 | Casper Editorial Team

Are you in the market for a new mattress, but unsure what size to get? When it comes to mattresses, size matters. You’ll want to find a mattress that works well with your sleeping needs and space. 

If you’re stuck deciding between a twin vs. full mattress, it’s important to know the main difference is in the width. A standard full-sized mattress is 15 inches wider than a twin mattress. However, both twin and full size mattresses are 75 inches long. 

Our guide will help you understand the difference between twin vs. full mattresses and include tips on how to find your perfect fit.

Our innovative twin size mattresses are made from multiple layers of cooling foam. Then they’re squeezed down into a tiny box, which magically appears on your doorstep within a few days.

Twin vs. Full Dimensions

  Twin Twin XL Full  Full XL
Length 75 inches 80 inches 75 inches 80 inches
Width 38 inches 38 inches 53 inches 53 inches
Surface Area 2,850 square inches 3,040 square inches 3,975 square inches 4,240 square inches

The main difference between twin vs. full mattresses is the width. A full-size mattress is 15 inches wider than a twin. To help you compare the two, we’re going to cover the major differences between Twin, Twin XL, Full, and Full XL mattresses.

People laying in separate beds of the following sizes: twin, twin xl, full, and full xl.

Twin (Standard)

Dimensions — 38” x 75”

Surface area — 2,850 square inches

Aside from a crib mattress, a standard Twin mattress (also known as a “single bed”) is the smallest mattress size on the market at 38 inches wide and 75 inches long. It’s compact and small, making it great for children, bunk beds, and small sleeping spaces.

Twin XL

Dimensions — 38” x 80”

Surface area — 3,040 square inches

A Twin XL is slightly larger than a twin mattress. It’s five inches longer than a twin with a surface area that’s about 6% larger — making it a great option for taller teenagers or adults who live in small spaces. Twin XL mattresses are about the same length as a King size mattress or a Queen size mattress but much less wide.

Full (Standard)

Dimensions — 53” x 75”

Surface area — 3,975 square inches

A standard Full size mattress (also known as a “double bed”) is 15 inches wider than the Twin XL but five inches shorter. A full mattress has a surface area that’s 30% larger than the Twin XL. This makes a great starter mattress for recent grads or young adults living on their own for the first time.

Full XL

Dimensions 53” x 80”

Surface area — 4,240 square inches

A Full XL is the same width as a standard full, however, it’s five inches longer. Full XL mattresses have a surface area that’s 6% larger than a standard full at 4,240 square inches. This makes it a great option for taller adults who find the standard full a bit too short.

Differences Between Full and Twin Mattresses

Chart showing differences between Full and Twin Mattresses (Price, Accessories, Room Size, and Uses)
Aside from dimensions, there are several other factors that may contribute to your decision process including price, room size, accessories, and specific uses.


The price of a mattress depends on a number of factors including the brand, material, type of mattress, and size. When it comes to the price of twin vs. full mattresses, twin mattresses are usually the cheaper option because they’re smaller. Generally, the larger the mattress, the more expensive it will be.

For example, check out the difference in price between our Casper Original Mattress:

  • Twin — $895
  • Twin XL — $995
  • Full — $1,195

If you were to buy a hybrid mattress, the price would be a bit higher because of the material used. Take a look at the difference in price between our Original Hybrid Mattress:

  • Twin — $1,295
  • Twin XL — $1,395
  • Full — $1,595

While the price difference is relatively small, it’s something worth noting if you’re shopping on a tight budget


Something to also keep in mind is the accessories needed for your specific mattress size. It’s easy to find sheets and bedding that will fit both twin and full mattresses, however, they will differ in price.

Just like mattresses, the price of bedding, pillows, and other accessories will depend on the brand, material, and size. Twin bed sheets will typically be cheaper than full size sheet sets because they’re smaller in size. 

You’ll also need fewer pillows with a twin bed depending on the type of sleeper you are. Twin beds typically only need one pillow, while a full-size bed can fit two pillows perfectly.

You should also consider the price of a bed frame or base. Similarly to other accessories, full sized bed frames and bases are going to cost more than twin sizes. You can always go with a budget-friendly option like a platform bed, which doesn’t need an extra base to support your mattress.

Two separate rooms one, with a twin size bed and one with a full.

Room Size

When it comes to room size, it goes without saying twin mattresses are a better choice for smaller sleeping spaces. However, both twin and full mattresses can fit in pretty much any room and are great space savers.

Twin mattresses work best in rooms that are 10 x 10 feet or smaller to help save space without sacrificing sleep.

Twin beds work perfectly in:

  • Kids’ rooms 
  • Studio apartments
  • Other small rooms 

Twin XL mattresses work well in:

  • Hostels 
  • Studio apartments
  • College dorm rooms 

Generally, full mattresses will fit best in a room that’s 10 x 12 feet or larger. This will ensure there is extra space for furniture and other types of bedroom decor.

Full mattresses work well in a majority of rooms, but especially in:

  • Apartments
  • Small master bedrooms 
  • Guest rooms 


A twin size mattress is a great starter mattress for children when they’re transitioning from a crib into a “big kid’s bed.” If you have two kids sharing a room, twin beds are a perfect fit. They also work well for bunk beds. Once your little ones reach their teenage years, consider switching to a full if the twin becomes too small.

Full mattresses are ideal for single sleepers because of the extra width on each side. If you sleep with someone, a full-sized bed leaves each person about 27 inches of space. If you value your personal space, you may find a full is too small for two people.

You should also consider how you sleep. Certain popular sleeping positions can take up more room. For example, starfish sleepers sprawl out and take up a lot of space. Odds are, you won’t be able to change your preferred sleeping position, so it’s important to have a bed with enough space to spread out comfortably.

What Is a Twin Bed?

A person lounged on a twin-sized bed.
Also referred to as single beds, twin beds are the typical mattress option for kids that have grown out of their cribs. They are great space savers and work especially well in kids’ rooms and guest bedrooms.


  • Easy to move
  • Cheaper than a full mattress
  • Great for kids and toddlers
  • Can be used in bunk beds


  • Too small for teenagers and adults
  • Kids may grow out of them in a few years
  • Not as versatile as a full bed

Because of their small size, twin beds are cheaper than full mattresses and easier to move. However, they may not last your little one long if they have a growth spurt.

Casper’s Twin Beds

Casper offers Twin mattress options for all mattress models. They’re vacuum-sealed and packaged in a box so you can easily set up your new mattress wherever you’d like.

Casper’s Twin beds are the perfect choice for your little ones or any bedroom where you would like to maximize floor space.

What Is a Full Bed?

A person and their dog lounge on a full-size bed.

A full bed, also referred to as a double bed, is the ideal option for single sleepers looking to save space. While full mattresses are the same length as standard twin mattresses, they offer extra width and are a popular choice for guest rooms and small apartments.


  • Ideal for taller teenagers or young adults
  • Offers extra width
  • Easy to find accessories for
  • Works well in smaller apartments and guest rooms


  • More expensive than a twin
  • May be too small for couples
  • Not as easy to move

Because a full mattress is 15 inches wider than a twin, it’s a bit more expensive and harder to move. However, the extra width makes this type of bed ideal for both kids and young adults who live in smaller spaces.

Casper’s Full Beds

Full beds are a great option if you’re looking to get a bed for an older child, teen, or adult in a small space. With a Full size mattress, you’ll get a bit more space to stretch without taking up an entire room.

Should You Get a Twin or Full Bed?

When searching for a new mattress, consider who will be sleeping in the bed and where it will be placed.
You should choose a standard twin mattress if:

  • Your child has graduated from their crib and you’re shopping for their first “big kid bed.”
  • You’re looking to set up a bunk bed in your kid’s bedroom.
  • You’re looking for the most affordable mattress option.

You should choose a twin XL mattress if:

  • Your child is too tall for a twin and needs the extra length.
  • You live in a studio apartment.
  • You’re looking for a bed for a hostel.

You should choose a full mattress if:

  • You recently graduated college and are moving into a new place.
  • You’re a single adult living on your own for the first time.
  • You want a mattress that your child can grow into.

You should choose a full XL mattress if:

  • You sleep with someone else and like to cuddle.
  • A full mattress is too small for you and you need the extra leg room.
  • You don’t have the space for a king or queen mattress.


What’s the Difference Between a Full and a Twin?

A full bed is 53 inches wide while a twin bed is 38 inches wide. Both mattress sizes are 75 inches long.

What’s the Difference Between a Twin and a Twin Full?

Full mattresses are sometimes called twin full. Compared to a twin-sized mattress, a twin full (put simply — a full mattress) is the same length and 15 inches wider.

Is a Full or Twin Better?

Twin and full mattresses are best suited for different situations. For smaller spaces — or sleepers, a twin is best. For older children to adults who don’t have the space for a queen or king mattress, a full mattress is best.

Is a Twin Bed Big Enough for Two People?

While two small children might fit on a twin bed — it’s not suitable for long-term sharing at any size.

Is There a Bed Size Between Twin and Full?

A Twin XL is five inches longer than a twin or full mattress, so it offers a bit of extra legroom. However, it’s the same width as a standard twin.

Is a Full Bed Big Enough for a Couple?

A Queen mattress is the most popular bed size for couples. But two people can fit on a full mattress if they don’t mind sleeping in close quarters.

Once you’ve decided between a twin vs. full mattress, the real fun begins! Choose between memory foam, latex, a hybrid mattress, and more. Make sure to pick out some cozy bedding as well.

Looking to compare other mattresses? Check out our King vs. California king and Full vs. Queen mattress comparison guides to help you find the mattress that works for you.