Mattress Size Chart & Dimensions Guide

Unless you’re looking for a custom mattress size, like one to fit a particular space in your home or an RV, sizes are pretty standard across the board. In other words, a twin mattress from Macy’s will be the same size as a twin mattress from Tuft & Needle or Casper.

mattress size chart guide

Below, we discuss in detail the dimensions of twin, twin XL, full, queen, king, split king, and California king beds. If you do happen to be in the market for a custom size mattress, though, learn how to get your hands on one at the bottom of the page.

Feel free to use the links above to jump to your desired mattress size. We even mention the more obscure mattress sizes such as the double and three quarters.

Twin Mattress Dimensions: Length & Width

Twin mattresses are best for the average child, starting from the time they outgrow their toddler bed to the time they’re pre-teens, or even early teens if they’re short enough.

A standard twin mattress is 38 x 75”; roomy enough for small humans, but probably too small for your average adult — even if they’re a lone sleeper. It’s the smallest bed size that most mattress companies make, besides Avocado who offers a crib-version of their popular Avocado mattress. Here’s our list of the best twin mattress options on the market today.

Twin XL Mattress Dimensions: Length & Width

Slightly longer than a twin mattress, a twin XL is made to accommodate taller individuals, or single sleeping adults who have a smaller living space. Like college students in dorm rooms, or bunk beds in vacation homes, for example.

Mattress Sizes Twin Twin XL Dimensions Graphic
The difference between a twin mattress and a twin XL

A twin XL mattress is the same width as a standard twin XL mattress, but it’s 5” longer. Their dimensions are 38 x 80”. So let’s say you’re a single adult in a small one bedroom apartment, or you’re in a college dorm with three different people, you’ll probably want to turn to a twin XL mattress.

Full Size Mattress Dimensions: Length & Width

This is where we start getting to more ideal adult sizes. A full size mattress, as you can probably guess, is larger than a twin XL but not yet as big as a queen mattress. It’s great for single adults, single adults with pets and or a small child, or even a teen’s room if the space allows for it.

The exact dimensions of a full size mattress are 54 x 75”. With this amount of sleeping space, we wouldn’t exactly recommend it to two people who share a bed together, as you’d have a whopping 27” of sleeping room to yourself. Unless you and your partner are major cuddlers trying to save money, then by all means try it.

Mattress Sizes Full Mattress Dimensions Graphic
The dimensions of a full or double bed

Also, just a heads up, you might come across the word “double bed” during your mattress search. But don’t worry, it’s really just another word for “full.”

Queen Mattress Dimensions: Length & Width

A queen size mattress can be comfortably shared between two bodies, whether it’s two human bodies or one human and one giant furry friend. The dimensions are 60 x 80”, so you have significantly more space than you would on a full mattress.

Mattress Sizes Queen Dimensions
The queen size mattress is (usually) big enough to fit two people

A queen bed is actually the most popular mattress size in North America. It can accommodate two people and or a single individual who wants to sprawl out, and it’s more budget and space friendly than a king size mattress. If you’re a couple who lives in a one bedroom apartment, for example, we’d definitely recommend a queen.

Take a look at our list of the best queen mattresses, including Brooklyn Bedding Signature who ranked in our top favorites because we think it’s such a good value.

King Mattress Dimensions: Length & Width

For relatively tall individuals and couples who have enough space in their room, a king mattress is definitely the ticket. It’s even big enough to where most couples can fit a few animals on with them, like my (Slumber Yard member McKenzie Dillon) S.O.’s parents who sleep with one big, bed hogging golden doodle at night.

Unbeknownst to some folks, king beds are actually the same length as queen mattresses — they’re just wider. The dimensions are 76 x 80″. So if you’re looking for that extra length, you’re not going to get it in a king bed. For those of you who are of average height and single, we’d probably suggest that you save money and go with a queen bed instead.

Mattress Sizes King Split King Dimensions Graphic
Split king mattresses are separated down the middle, and each side works independently from one another

Split King Dimensions

Split king beds are typically the size of two twin XL mattresses side by side; 38 x 80” and 38 x 80”.

Let’s say you’re a back sleeper and your partner is a side sleeper. If you purchased a split king mattress, one half of the bed can be soft to accommodate the side sleeper, while the other half can be firm and accommodate the back sleeper. It’s completely split down the middle, so each side feels and moves independently from one another.

Split king mattresses are also great when you pair them with adjustable bed frames. If one person were to get surgery, for example, the recovering individual can keep their leg/foot/knee etc. elevated, while their significant other can sleep completely undisturbed.

California King Dimensions: Length & Width

A California king mattress is like a super-sized bed. Its exact dimensions are 72 x 84”, meaning it takes up less space in width than a normal king size bed, but it is 4” longer.

Mattress Sizes CA King Dimensions Graphic
The California king mattress is one big bed

We think CA king beds are for extra long individuals or couples, like our resident tall-man JD who’s 6’5 and has little extra room on a king bed, or even for people who have a lot of extra space to fill in their master bedroom.


Other Mattress Sizes

The mattress sizes we mentioned above are without-a-doubt the most popular, but we want to make sure to note the more uncommon size possibilities available out there as well.

Crib Mattress: If you’re looking to furnish your baby’s crib with a comfortable mattress, you have plenty of options in both the online space and in brick-and-mortar retail stores. We mentioned earlier how Avocado offers their own crib mattress, but you can find a lot more affordable options as well. Crib sizes are actually regulated by the Consumer Products Safety Commission, who requires crib mattresses be a minimum of 27 1/4 x 51 ⅝”. They also must not exceed 6” in thickness.

Three Quarters Mattress: No we aren’t talking about Alice in Wonderland beds. A ¾ size mattress is a typical mattress that you’d furnish your RV, house boat, yacht, daybed, or even your tiny house with. Their dimensions are 48 x 74”, meaning they’re wider than a twin bed, but not quite as long.

Split Queen: Earlier we talked about a split king mattress, and its distant sister is a split queen mattress, otherwise known as a “dual queen.” They measure out to be 30 x 80”. We don’t see this size offered very often, but it does happen. So if you seriously want a split bed, but don’t have the space or funds for it, try searching the web for a split queen mattress.

Grand King: A California king is a big enough mattress for most people. If you’re not like most people, there is such a thing as a Grand king mattress which totals out to be 80 x 98”. It’s rare, but anyone who wants one can get their hands on one. The question is, why would you want one? For starters, if you’re an NBA player tall, like 7 ft, a CA king mattress is still too small. We’ve also seen the parents of big families with young children buy a Grand king mattress. That way, they can all comfortably fit on the bed for family movie night, nighttime bed stories, etc.

Round Mattresses: If you’ve ever seen a cheesy 60-70’s movie where the protagonist goes to a honeymoon suite furnished with red linens and a circle mattress– that’s what we’re talking about. There honestly is no reason to have a circle mattress, unless you’re going for a certain aesthetic. Shaquille O’ Neil, for example, in his episode of MTV Cribs, showed off his circle Superman bed. They’re typically measured in diameter, aka the length from one side of the bed to the other. They can be 76″ in diameter, or even more if you get into custom mattresses.

Purchasing A Custom Size Mattress

Some people may need to custom order a mattress to fit their particular space or needs. Many people with antique bed frames have to custom order a mattress, since beds before the 20th century didn’t come in standard sizes. People either had to make their own, or could have one made for them if they were rich enough. So if you have an antique treasure on your hands, or have taste similar to Shaq and want a super unique mattress, you’ll have to place a custom order.

Most name brands you’re familiar with like TempurPedic and Casper don’t do custom beds. To custom make a mattress, we suggest looking around at your online options like Custom Mattress Makers, Custom Mattress Factory, or

Through these sources, you’re able to customize just about everything from the mattress’ materials, firmness, and of course, the dimensions. Just make sure you compare prices before you pull the trigger on a custom mattress, they can get pretty pricey and we want to ensure you save the most money possible on your next new bed.