Mattress Size & Dimension Guide: Width, Length, & Height of Standard Mattresses

The most common mattresses come in six standardized width and height dimensions. The thickness of your mattress will depend on the manufacturer. Be sure to pay attention to the thickness of the mattress you purchase, as it may affect the size of the fitted sheets you will need to use.

Twin Size Mattress Dimensions

A twin-bed mattress measures 38 inches in width by 75 inches in length, and a standard twin-size mattress height is eight inches. If you have a toddler or a teenager at home, a twin-size bed would likely be perfect for them. And speaking of children, if you’re looking into adding bunk beds to a rental property or your kids’ room, they’re usually designed with twin mattress dimensions in mind. 

This mattress size also works wonders in a smaller guest bedroom as it is big enough to fit a single adult if they are not taller than six feet.

Twin XL Size Mattress Dimensions

The only difference between a twin and a twin XL mattress is that a twin XL is five inches longer than a twin, or 80 inches in total. The width of both is the same at 38 inches. This makes them an excellent option for a college dorm room, a guest bedroom or the room of a taller teenager. Twin XL mattresses are designed for single users and can’t comfortably fit a couple.

Because their measurements are so similar, manufacturers often produce twin and twin XL bedding with the same dimensions. The only exception would be a fitted sheet since it needs to match the exact measurements of the mattress.  

What’s the Size of a Full Mattress?

Also known as a double mattress, full-size mattress dimensions are 54 inches wide by 75 inches long. Double beds can best accommodate a single adult, providing them with plenty of space to sleep on. Alternatively, they can also fit a single adult with a small child or a pet. If you live in a studio apartment or your bedroom is on the smaller side, a full-size mattress would be the best choice for you. The generous full-size mattress measurements also make them an excellent option for a guest bedroom. Your visitors will certainly appreciate all the extra space this mattress gives them, over and above a twin-size mattress.

For more info on double beds, see our article: Double Bed Size: How Big Is a Double Bed?

Queen Size Mattress Dimensions

The most popular and standard mattress size measures 60 inches wide by 80 inches long. This is the best bed size for couples. Queen mattress dimensions are perfect for a traditional master bedroom in a house or an apartment. They can fit two adults or an adult and a child with a good amount of space left for both. Bedlinen for this type of mattress is widely available. In fact, bed sheets for full size and queen size mattresses usually have the same measurements. That’s because the difference between the length and the width of the two is only about five inches.

If you love hosting couples, you might want to furnish your guest bedroom with a queen size mattress.

King Size Mattress/California King Size Mattress Measurements

King size mattress dimensions are 76 inches wide by 80 inches long. That’s the equivalent of two twin XL beds, which is plenty of space for two people. This mattress size is probably too big for a single person unless you love to lounge in your bed and your master bedroom is big enough to fit it.

If you or your partner are taller, consider a California King size mattress. They were popularized in the middle of the last century by celebrities and athletes living in the Golden State who needed oversized beds to match the grandeur of their mansions. A California King mattress’s dimensions are 72 inches wide by 84 inches long. That’s four inches longer and four inches narrower than a standard king mattress’s dimensions.

Crib Mattress Dimensions

A crib mattress is designed specifically to fit safely in a standard crib. It measures 52 inches long by 28 inches wide. There shouldn’t be a gap more than two fingers wide between the edges of the mattress and the crib frame for safety reasons. Crib mattresses are extra firm to avoid forming pockets around your little one.

When selecting a mattress for yourself, keep in mind that if you are planning to have a baby, you need to have enough space in your bedroom to accommodate a crib bed for at least six months.

Learn more about transitioning your baby from a crib to a toddler bed in our post: When Should Your Baby Make the Transition From Crib to Toddler Bed?

The perfect mattress will not only be the right firmness but also the right size. First of all, take into consideration the bedroom dimensions. While there is no universal rule of thumb here, any mattress that leaves less than two feet of space between the bed and the walls will likely be too big for most people. Also think about the extra furniture you’d like to add to your bedroom — a nightstand or two, maybe a dresser or an armchair. Then calculate how much space you’d ideally have between the mattress and all of these furniture pieces without the bedroom looking cluttered.

Another factor to consider is, of course, how many people will be sleeping on the mattress. For singles, twin, twin XL and full-size mattresses are the best choice. Couples and parents should look into queen, king or California King beds. And finally, your height and preferred sleep position will also play a role in determining the best mattress size for you.

There’s a lot that goes into finding a good mattress. Your overall comfort will depend more or less on your mattress’ firmness. For example, if you suffer from back pain, you should look into mattresses that provide extra support, like the Eco Mattress. Talk to your doctor before purchasing a mattress to ensure it won’t worsen your pain over time.

Your sleeping position is also a significant factor. Back and stomach sleepers might find a firm mattress more comfortable, while a soft to medium-firm mattress may best accommodate side sleepers.

And then there’s the material that the mattress is made from. Nowadays, you can find foam, latex, innerspring and hybrid mattresses, each delivering a unique sleeping experience.

Read more tips about buying a new mattress in our Decision-Making Guide for Buying the Right Mattress.

Just like comfort is subjective, so too are decor aesthetics. While there is some room for variation based on your style preferences, in general you should use blankets and sheets that match the dimensions of your mattress. As previously mentioned, this is also when you need to pay attention to mattress depth. Most fitted sheets are manufactured with a pocket deep enough to fit a 16-inch mattress, so a mattress much thicker or thinner than that may need custom-ordered fitted sheets.

Flat sheets, duvet covers and blankets are usually manufactured with larger measurements, so even if they don’t match the exact mattress size, they will still do a good job.

Just keep in mind that the top bedding layer of your bed — usually a quilt — should be longer than any other underneath it for a tidy and neat look.

For more advice on choosing the right bed sheet and blanket sizes, read on in our Bed Sheet, Blanket, and Quilt Size and Dimension guide.