Our article title is actually a trick question. Double beds and full size mattresses have the same dimensions—54 inches wide and 75 inches long, or roughly 137 centimeters by 190.5 centimeters.
A Brief History of Double Beds
A double mattress sounds like a bed meant for two people to share, and once upon a time, it was. Many decades ago, double or full beds were the mattress choice for couples, but this is partly because consumers then didn’t have as many size options as we do now. The size is no longer recommended for couples, only for single sleepers.
In the 1940s, couples could either share a double bed or purchase a pair of twin mattresses. You might have seen the classic setup of two twin beds with a nightstand between them in an old black-and-white TV series.
Separate beds were a common choice for couples until the 1950s, which is when refusing to share a bed became viewed as a sign of a failing marriage. The 1950s were also when queen and king size mattresses became popular. People were making more money, and the average person was growing taller than their parents, necessitating bigger beds.
The rise of king and queen mattresses caused the double bed to fall out of favor with couples. Many people today would not find it a comfortable bed to share since each half would only measure 27 inches by 75 inches—which is perhaps enough room to lie down but may not provide enough personal space to turn without hitting your bed partner.
A double or full size mattress remains an excellent choice for single adults who have limited space but want a bed bigger than a twin.
Difference Between Full and Queen Mattresses
The other mattress size you’ll likely see associated with full mattresses are queen size mattresses. While the two are not the same size, they are close enough that many compare full and queen size mattresses.
A queen size mattress’s dimensions are 60 inches of width and 80 inches of length. That makes a queen mattress 6 inches wider and 5 inches longer than a full size bed. The difference is minimal enough for you to see loose bedding items such as comforters marketed for both full and queen mattresses.
The most significant difference between the two sizes is how many sleepers the mattress can accommodate. A queen size mattress is an excellent choice for couples who want a bed to share. However, a full size mattress is best reserved for single sleepers who want the room to sprawl.
Variations: Full XL Size Mattresses and Small Doubles
It’s common for a mattress size to have variations with slight size changes, such as the twin and twin XL mattresses or king and California king mattresses. The dimensions of a full size mattress are no exception. A full size mattress has a couple of different variations—the full XL size mattress and the small double.
A full XL mattress offers 5 more inches than the standard full size mattress, with no difference in width. It’s an uncommon size, so you’re unlikely to find it at a mattress store and may have to purchase one from an online mattress brand. The rarity of a full XL size mattress can make it difficult to find a matching bed frame and bedding.
Small doubles are a typical bed size in the United Kingdom and Ireland. As the name implies, a small double mattress takes up less space than a traditional full size mattress, measuring 48 inches wide and 75 inches long. A small double may also be called a queen, not to be confused with the United States’ much larger standard queen.
More Bed Sizes
There’s more than just a full size mattress to consider when you’re shopping. Perhaps a full bed is too big for a small bedroom, or it’s not big enough for your sleep needs. You might want to consider other mattress sizes: twin, twin XL, queen, king, and California king beds.
A twin size mattress is the smallest standard size that an adult should consider. It’s only 38 inches by 75 inches, able to squeeze into most small bedrooms. You may also see a twin mattress referred to as a single bed, much like how double and full are both names for the same size mattress.
A twin bed is an excellent addition to any children’s room—you can even opt for two and save on space with a bunk bed. The dimensions of a twin size mattress make it a perfect choice for a daybed, which is similar to a sofa and excellent for lounging and relaxing.
A twin XL size mattress is 5 inches longer than the standard twin, bringing its total dimensions to 38 inches by 80 inches. Twin XL mattresses are a suitable size for anyone over 6 feet tall. Sleeping on a too-small mattress can leave your feet dangling over the edge or cause you to develop an unhealthy sleeping posture.
Twin XL mattresses are a good choice for a growing child, able to accommodate most through their teen years. It’s also a suitable size mattress for a smaller guest room, providing enough space for the average single person. The mattress’s versatility is why many college dorms contain twin XL beds.
As we mentioned earlier, queen size beds are 60 inches by 80 inches. They’re the most popular size because they suit a wide range of sleepers, from couples shopping on a budget to single sleepers looking for a luxurious mattress.
Queen mattresses are a common choice for couples who want to share a bed because of the bed’s affordability and the fact that a queen can fit in most bedrooms. However, some couples might prefer the space that a king mattress offers. If you’re interested in comparing the two, read our king vs. queen guide.
Do you need a size larger than a queen but not quite as large as a king? There are nonstandard options you can consider, such as the Olympic queen and the California queen. An Olympic queen has 6 inches of extra width, while a California queen is 4 inches longer. Though uncommon, you should be able to find these size variations online.
At 76 inches wide and 80 inches long, a king size mattress is the largest standard size. It’s large enough to accommodate most couples, with each half equal in size to a twin XL mattress.
Couples may want to consider the benefits of a king mattress split into twin XL size halves. Known as a split king, this design lets each partner sleep on their preferred firmness. It also allows each half of the mattress to move independently on an adjustable bed.
But while split kings can offer more comfort for couples, they are typically more expensive than the already costly king size bed. For a full comparison between the two, you can read our split king vs. king guide.
There are nonstandard sizes larger than a standard king, such as the Wyoming king, the Alaska king, and the Texas king. These oversized options often have to be specially ordered from a custom mattress maker.
A California king size mattress is 72 inches wide and 84 inches long. It’s almost as if 4 inches get taken off the side of a standard king bed to make the mattress longer. At 7 feet long, a California king mattress can accommodate most tall sleepers.
Just like how a full bed is sometimes referred to as a double, you might see a California king mattress referred to as a Western king. A standard king mattress is sometimes called an Eastern king in response.
Aside from the slight difference in dimensions, a California king has a lot in common with a standard king. Both sizes tend to have similar prices and are best used in bedrooms at least 12 feet by 12 feet.
Do you find yourself undecided between a king or a California king mattress? Our king vs. California king guide covers the pros and cons of each, making it easier to determine which is right for you.
Frequently Asked Questions
A full size mattress dimensions are 54 inches by 75 inches, while a queen mattress measures 60 inches by 80 inches. That makes a queen mattress 6 inches wider and 5 inches longer. A queen mattress offers 750 more square inches of sleeping space than a full size mattress.
We can’t recommend that two adult sleepers share a full size bed, even if that was once a popular purpose. While two adults can probably squeeze onto a full mattress, it wouldn’t leave sleepers with a lot of room to move. Each side would only have about 27 inches, around the same width as a crib mattress.
Whether a twin or a full mattress is the better choice for you depends on your sleeping preferences, bedroom size, and budget. A twin mattress is a more affordable and space-efficient option, making it an excellent choice for a young adult’s first mattress.
A twin and a full size bed are only recommended for single sleepers. If you’re shopping for a mattress to share with a partner, we advise against any bed that’s smaller than a queen.
A bedroom that’s 10 feet by 10 feet is a good size, able to accommodate most mattress sizes. You can easily fit in a full size mattress or even a queen bed. However, if you’re considering a king size mattress, you’ll want a bedroom that’s at least 12 feet by 12 feet.
If you don’t remember your bed size, you might be able to double-check your mattress order. It’s always a good idea to hang onto a proof of purchase to make a warranty claim, so just pull out the receipt and see if it specifies what size mattress you bought.
And if the receipt doesn’t mention your mattress size and you have no other way to look it up? Then it’s time to break out the measuring tape and measure your bed's length and width. Remember, standard bed dimensions are as follows:
- Twin: 38 inches by 75 inches
- Twin XL: 38 inches by 80 inches
- Full: 54 inches by 80 inches
- Queen: 60 inches by 80 inches
- King: 76 inches by 80 inches
- California king: 72 inches by 84 inches
Folding a foam or hybrid mattress for a short time, such as when moving a mattress from one room to another in your home, shouldn’t damage your mattress. However, keeping a mattress folded for a longer period, such as a cross-country move, may adversely affect your mattress. If you want to take a foam mattress with you when you move, take a look at our mattress compression guide.
Did We Help?
It can be confusing to see multiple names for the same mattress size. Full/double beds aren’t the only size with this issue, as you’ll often see different names for twin, queen, and king sizes. When in doubt, try relying on the mattress’s measurements to determine if it’s the best mattress for you.
This article is for informational purposes and should not replace advice from your doctor or other medical professional.