What Are The Differences Between Mattress Sizes

What Are the Differences Between Mattress Sizes

December 24, 2018
Healthy Sleep

With all the different traditional mattresses and custom mattresses available like waterbed inserts on the market today, it can get quite confusing. Here is a primer to guide you to getting the right size for you, your sleeping situation, your bedroom size and just getting a mattress that you and yours will be comfortable in.

If someone asks you what size mattress you have and you answer a King. Is it a King, California King, Western King, Eastern King or a split King? Did you realize that there’s much more to the size than King size? Here is an explanation of all the many sizes of traditional and non traditional sizes offered so you can get the correct size that is best for you.

Standard King/Eastern King

A standard King and an Eastern King are the same exact size, they are just sometimes called a King size but all the measurements are the same in all three instances no matter which is identified as the size. A King is best for a couple that loves to stretch and sprawl out and they may even have a pet join them in bed at night. King size mattresses are 76 inches wide and 80 inches long and are made for a king. You will notice that most boxpsrings for these beds are in two pieces. In fact they are actually two twin extra longs placed side by side. This makes for ease of delivery and mobility. A King works well in a room that is at least 10 feet by 12 feet and have space for two nightstands and a dresser as a cozy fit. If your bedroom is larger than this, you will have more room on the floor and it will be less cozy a fit. The ideal size room for a King bed is 13 feet square up to 13 feet by 19 feet.

California King/Western King

The California King and Western King are the exact same mattress that is sometimes called one name or the other. This size mattress is also great for a couple to sprawl and stretch out but is extra nice for people  that are taller, especially those over 6 feet tall. Originally made popular as a waterbeds size the California King developed it’s niche and differs from a standard King because it has additional length rather than width sometimes helping with the fit in a smaller bedroom. A large bedroom that is 13 feet by 19 feet can hold a standard King bed, two nightstands, a dresser, a TV stand and a cozy chair of some sort. However, if your bedroom is a bit smaller such as 10 feet by 12 feet, it can hold a California King, two nightstands and a dresser. The California King is 4 inches narrower and 4 inches longer than a traditional King making it 72 inches wide and 84 inches long. When purchased as a waterbed insert it will measure two inches narrower than a traditional California King and is 2 inches longer and fits existing wood framed waterbeds.


The number one selling size in the nation, a queen size mattress works in a number of sleeping situations. They are great for a couple, a teenager or young children with parents that like to read them a nighttime story in bed or even a single person with a dog. A Queen size bed needs at least 9.6 feet by 10 feet in a bedroom to have adequate space to walk around the bed. The best selection of bedding, stock, and prices are often found when purchasing queen so keep that in mind if you don’t mind being a little bit closer to your partner. You can fit a Queen size bed in a room that is 10 feet square up to a bedroom that is 10 feet by 14 feet, depending on how much other furniture you have in the room. A Queen mattress measures 60 inches wide by 80 inches long and it is an extra 7 inches wider and 5 inches longer than a Double or Full size bed.

California Queen

A California Queen was also a popular waterbed size. Not often found in conventional mattresses, but the bed works in all the same sleeping situations as a traditional Queen. It is also ideal for taller people. Take note that it does differ from the Queen in measurements though. It is also a great fit for the same size room of 9.6 feet by 10 feet up to a bedroom that measures 10 feet by 14 feet. The California Queen mattress measures 60 inches wide and 84 inches long. When purchased as a waterbed insert it will measure two inches narrower than a traditional Queen and is 2 inches longer than a traditional Queen size and fits existing wood framed waterbeds.


The Full and Double size bed are the exact same in measurements–they just are labeled differently by some manufacturers. Once the bed of choice for adult couples is now most popular in the kids room or spare bedroom. This size bed will also work in many sleeping situations for a couple, a teenager or young children that have parents that read to them in bed, or a single person with a dog. A bedroom needs to be a minimum of 9 feet by 9.6 feet to have an adequate amount of space to walk around it; however the average room size for a Full bed is about 10 feet by 12 feet. A Full mattress is 54 inches wide and 75 inches long. Even though it is called a Double bed, this bed is not actually two times the size of a Single/Twin bed. It is actually only 15 inches wider than a singe bed.

Twin XL/Single XL

The Twin XL and Single XL are the same size bed and as the name implies, they are longer than a traditional Twin/Single mattress. It is a great choice for teens, tweens, and adults looking for the length of a King or Queen Mattress.  They are also great for a guest bedroom and college dorm rooms for one person. The minimum size room with walking room around the bed would be 8 feet by 10 feet. The Twin XL is 38 inches long and 80 inches long.


The Twin or Single bed is the same width as a Twin Xl/Single XL but is 5 inches shorter in length. This works in the same sleeping situations as the longer XL versions for people who are side sleepers and don’t need the extra length in a mattress. It fits in a smaller room that is a minimum of 9 feet square with room to walk around the bed and even place two twin beds in the room. This size is also commonly used as bunk beds for two children in one room. Make sure and factor in the extra height if you are buying bunk bed mattresses. Twin mattresses are 39 inches wide by 75 inches long.

Waterbed Inserts

Many homeowners lose their love for the motion of a waterbed, as they get older and choose instead to get a mattress insert that is like a traditional mattress for a waterbed frame. There are a few things to note when you do this. The waterbed frame cavity will be 2 inches wider and 2 inches longer than the actual waterbed insert. The inserts are made in this manner so you can easily make your bed and tuck the fitted sheets inside the waterbed frame without a need to lift the mattress or pinch your fingers. Common sizes of waterbed inserts are Twin, Twin XL, Full, Super Single, California Queen, California King, Eastern King and Eastern Queen. Each of the inserts are 2 inches narrower and shorter than the waterbed frame whether your frame is a hard side or soft side style.

Split Mattresses

Split mattresses are commonly used by couples on an adjustable foundation so that each partner has control over their side of the bed independently from the other. The most common split mattress sizes are Split Queen and Split King. The two separate mattresses put together are the exact same measurements as a traditional Queen and King mattress.

This summary of all the different types and sizes of mattresses as well as the sleeping habits and room sizes can help you to decide the perfect mattress for your specifics.