Mattress Guides

What’s the Difference Between a Double Bed and Full Size Mattress? 

By Liam Hinton, August 24, 2022

The terms “double bed” and “full size mattress” are often used interchangeably. Although this phrasing can be confusing when shopping for a new bed, these names refer to the same mattress size—54 inches by 75 inches.

This mattress size is a common choice for both single adults and children alike. Plus, it requires less space and is not as bulky as queen and king size beds. Throughout this article, we provide some history on the double bed, its dimensions, benefits, and some of the size variations you may encounter when shopping.

History of the Double Bed

As its name suggests, double beds were initially designed for two sleepers. However, before the 1940s, doubles were one of the few mattress sizes available. These beds were also one of the largest, which is perhaps where the name “full” comes from.

In the 40s, couples could choose to sleep on two separate twin beds or share a double bed. After the economic boom of the 1950s, Americans began to demand bigger, more luxurious home furnishings. The average American height and weight also began to increase at this time, creating an urgent need for a more spacious mattress.

As the demand for queen and king size mattresses grew, double beds were no longer a popular choice for couples. With only 27 inches of space per side, a full mattress is often too confining for two adult sleepers. A queen or king size bed offers couples more personal space to stretch out.

Dimensions of a Double/Full Mattress

Double beds measure 54 inches wide by 75 inches long. While these mattresses have the same length as a twin size bed (75 inches), they are 16 inches wider. For children and teenagers who have outgrown their twin mattress, a double bed is a good choice. Growing kids need plenty of room to move around and get comfortable during the night.

Single sleepers who prefer a bigger bed, but have a smaller room, may also like a double bed. These mattresses fit comfortably in most standard-sized bedrooms, including those that measure 10 feet by 10 feet (100 square feet).

Size Variations

Full XL or Double XL

As you shop for a full/double mattress, you may come across two size variations. Mattresses labeled “full XL” or “double XL” have the same width as standard full/double beds. However, the XL version of this mattress size measures 5 inches longer. The extra length is great for taller individuals in need of more legroom. With a total of 80 inches in length, tall sleepers won’t wake up with their feet dangling off the end of the bed.

Full/double XLs are not very common, but they are available at some online mattress retailers. When purchasing an XL model, keep in mind that accessories, such as sheets and bed frames, may be harder to find. Since this is not a popular size, not all manufacturers offer bedding that accommodates the extra length. As you shop, look at the dimensions of bedding and bed frames—this will help you determine if the item will fit a full/double XL mattress.

Small Double

Although they are not very common in the US, mattresses labeled “small doubles” measure 48 inches wide by 75 inches long. This size is typically found in the United Kingdom and Ireland. Small doubles may also be referred to as a “three-quarter bed.” Like a standard double, small doubles are not recommended for two sleepers.

How Do Full/Double Beds Compare to Other Mattress Sizes?

In addition to double beds, there are several other standard size mattresses available in the United States. The most common include twin, twin XL, queen, king, and California king. Below, we explain how full/double size mattresses compare to these other sizes.

As we mentioned above, twin and full size mattresses both measure 75 inches long, but fulls are 16 inches wider than twins. Both sizes are suitable for most bedroom sizes, while still leaving enough space for furniture.

Twin XL mattresses measure 38 inches wide by 80 inches long. They have less width than a full but are 5 inches longer. Twin XL beds are typically used in college dorm rooms to accommodate taller students. Some bunk beds are also now available for twin XL mattresses. Although the length may work for most sleepers, some adults find the width of a twin XL too confining.

Queen mattresses are 6 inches wider and 5 inches longer than a full size. With 30 inches of space per side, a queen bed works well for most couples. This size is also a popular option for a guest room or a vacation home. However, if your family prefers to co-sleep, you may need more width so you, your partner, and your children can sleep comfortably. In most cases, a king size mattress works best. The extra width of a king bed offers 38 inches on each side of the bed.

California king beds are 4 inches narrower than a king, but 4 inches longer. Taller couples may prefer a bed with additional legroom.

If you decided to purchase a king or a California king mattress, be sure you have adequate space first. Larger mattresses require a room that measures at least 10 feet by 12 feet (120 square feet). A master bedroom that measures 14 feet by 16 feet (224 square feet) works even better in most cases. This room size should leave at least 2 to 3 feet of space around the mattress to make getting in and out of bed more comfortable.

Standard Mattress Sizes

Mattress SizeMattress Dimensions
Twin38 inches by 75 inches
Twin XL38 inches by 80 inches
Full54 inches by 75 inches
Full XL54 inches by 80 inches
Queen60 inches by 80 inches
King76 inches by 80 inches
California King72 inches by 84 inches

Why Get a Full/Double Mattress?

Although larger bed sizes are more suitable for couples, double beds offer solo sleepers several benefits. Below, we outline why a full size mattress might be right for you.

  • Limited Space: As you shop for a new mattress, you should consider the size of your space. For a small studio apartment or a house with small rooms, a queen or king mattress may not be a good fit. However, a full size bed fits well in most spaces, without causing the room to feel overcrowded. A double bed offers solo sleepers more room to get comfortable, without sacrificing too much living space.
  • Versatile: Full size mattresses are suitable for children, growing teenagers, and single adults. They fit well into most rooms and are readily available online. It is also easy to find accessories, such as foundations, sheets, and comforters for a double bed.
  • Budget-Friendly: Full size beds are a budget-friendly option when shopping for a child’s room or guest room. Full size bedding and mattress foundations are also less expensive than their queen and king size counterparts.
  • Easy to Move: Queen and king size mattresses can be heavy and difficult to move. If you plan to relocate soon, a full size bed may be the best choice. Double beds are typically lightweight and will easily fit into a van or small moving truck.

Frequently Asked Questions

How wide is a full size bed frame?

Most modern bed frames measure 1 to 2 inches wider and longer than the mattress itself. This extra space accounts for bedding that may hang down the sides and end of the bed. Therefore, a full size bed frame should measure 55 to 56 inches wide and between 76 to 78 inches long.

Are full size mattresses big enough for two people?

Full size mattresses are 54 inches wide, which leaves 27 inches on each side of the bed. While two people may fit on a full size bed, they will not sleep comfortably. Although larger beds require more space, couples typically sleep better on a queen or king size bed.

What’s the difference between a full XL and a queen bed?

A full XL mattress measures 54 inches wide by 80 inches long, while a queen size bed measures 60 inches wide by 80 inches long. These two sizes have the same length, but a queen is 6 inches wider than a full XL.

Can queen sheets fit a full bed?

No. Queen size sheets will not fit a full size bed. Queens beds are longer and wider than a full mattress. Sheets designed for a queen will not fit snug on a full size bed—leaving extra fabric on the side. This material may bunch up as you move throughout the night, causing discomfort and sleep disruptions.

Should I buy a queen or full bed?

If you are a solo sleeper looking for a more luxurious sleep space, a full bed is a good option. However, if you are over 6 feet tall, a full XL or a queen size bed may be more comfortable for you.

Most couples prefer a queen or king size bed. Full size mattresses are too confining, even for smaller couples. The right bed size will ultimately depend on your body type and whether you plan to co-sleep with children. Queen size mattresses typically work well for most couples, but those who prefer to co-sleep should select a king size bed.


Although the United States has standard mattress sizes, the various names can make selecting the right size confusing. To ensure you are bringing home the best mattress, look at the bed’s dimensions and compare those to your bedroom. This is also a great way to shop for bedding, mattress foundations, and bed frames.

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