Mattress Size Chart (US) – A Complete Guide

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written by sleep expert Lauren Hall

How to Choose a Mattress Size

When buying a mattress, it is important to determine what kind you prefer. But it is equally important to choose one that is the right width, length, and thickness based on your needs. Here is our mattress size chart.

It might seem simple, but this can determine your level of comfort and the quality of sleep that you get, sometimes even more than the kind of mattress itself!

How do you know what size is right for you? If you don’t get to test it out, how can you gauge the best thickness for your needs? Well, we have come up with a handy guide to the standard mattress sizes, and a supplementary guide to choosing mattress thickness, to help you out.

As a general rule, you should, of course, choose a size based on your body. The mattress you choose should be around 4” (10cm) longer than your height, at least.

In addition, a mattress with a comfortable width should have enough space for you to place your hands behind your head comfortably with your elbows extended without touching a sleeping partner or the edge of the bed.

In addition, keep in mind that apart from body size, you need to consider the size of your bedroom before making a purchase.

You may feel like you and your partner want all the space of a large bed, but if your room cannot possibly fit it, then you will likely need to opt for something smaller.

The fact is that what has changed the popularity of bed sizes over the years is the growing sizes of rooms and houses, so this is a very important area to consider.


Mattress Size Chart


This bed size for single sleepers is the smallest available one. It gives you 39” of width to roll around and is 75” in length.

They are typically used by children due to adults now preferring slightly larger sizes, but in the past were the most common kind of mattress size for single sleepers. They are also usually the kind of size used for bunk beds.

Twin XL (Extra-Long)

The Twin XL is designed to be similar to the Twin in width, but longer. They are 39” by 80” and work great for taller single sleepers.

Full (Standard / Double)

Formerly the most popular size of bed for couples, full or standard beds measure 54” in width, with a length of 75”. Sleeping with a partner on a full bed will provide you with approximately 27” of sleeping space for yourself.

Due to the increasing size of homes and, therefore, bedrooms, these beds are no longer the norm for couples, instead opted for by single sleepers who want extra room to wiggle around in. Some couples may even find this kind of bed too small for comfort.

Full XL (Extra-Long)

Full XL beds are the same width as Full beds at 75”, but allow for taller sleepers with an extended length of 85”.


The 60” wide and 80” long mattress is the most popular size in all of the United States. This is the go-to size for couples and those who co-sleep, providing a nice 30” of space per person to sleep on.

King (Eastern King)

King-sized is 80” long, like Queen sizes, but are 76” wide. This is often chosen by couples who tend to sleep with space between them or have others sharing the bed, like young children or pets.

Keep in mind that king-sized beds take up loads of room, so you have to make sure your bedroom is equipped for it!

There are also options on the market to purchase a “split King” mattress – due in part to the fact that most King box springs have to come in two pieces because they are too large to easily maneuver.

If you do purchase a split King mattress, you will actually be buying two Twin XL beds. Either way, with 38” of sleeping space per person, you will be comfortable and good to go.

California King

The California King is quite different from the traditional King mattress. It is not as wide, boasting only 72” in width, but it is 84” long and is, therefore, a great option for taller sleepers. It is, in fact, the longest size that you can purchase.

As with the King bed, it takes up quite a bit of room, so be sure that you can accommodate it before deciding to purchase it. This bed works well for couples, too, providing them with 36” of individual sleeping space.

Custom sizes

None of these dimensions fit the bill for you? There are plenty of stores that offer custom-sized beds tailored to your exact specifications.

While they definitely aren’t the norm and will make finding sheets, frames, and foundations rather difficult, some prefer to have this control over their bed and would rather have it sized perfectly than settle for less.

Mattress Thicknesses

Mattresses range in depth from 4” all the way up to 20”, usually in accordance with their other dimensions.

The thickness of a mattress can decide whether you sleep comfortably or not, and it also will determine other factors, such as the types of sheets or the height at which the bed stands off the ground.

Not sure what thickness is right for you? Let’s talk about some factors that go into choosing the right mattress depth.


Type Of Mattress

Mattresses come in all sorts of different types, but most have a minimum thickness that they can get to before the product simply becomes uncomfortable.

Innerspring mattresses are the original, traditional mattress that has steel coils inside them topped by layers of cushion. In previous decades, they normally clocked in at 6” to 8”, but now the industry standard has jumped to 11” to 15”.

Some manufacturers even make more luxurious options at 20”! In these cases, you want a mattress with a thickness that subsets the metal coils in the base so that you feel comfortable despite them.

Memory foam mattresses range from 6” to 14” thick in most products, though they can get much thicker. As a general rule, 6” and 8” mattresses of this variety are not the most comfortable.

However, you need to keep in mind that it is not the thickness of the mattress itself that matters the most in the case of this type – it is the thickness of the memory foam itself.

A thicker foam will make the bed feel softer, while the thinner memory foam will be more firm. However, the base support foam should be thicker than the memory foam layer in order to provide sufficient support and aeration.

On top of that, you will need to take into account the density of the foam itself to figure out how thick you need it to be for optimum comfort.

Latex foam mattresses usually come between 6” and 12” in thickness, but of course, there are companies that make them thicker.

With that being said, most mattresses of this variety below 8” in depth are uncomfortable and waste the potential of the latex foam.

Yet, some users don’t mind the 6” and do not feel it be too thin, so this is up for debate. Like with the memory foam mattress, the density of the latex foam used can determine what thickness of the overall mattress you require.

Adjustable air mattresses are fair game for a reason clearly stated in their name – they can be whatever thickness you like depending on the amount of air you put in!

Some even come with separators down the middle so that you and your co-sleeping partner can have different thicknesses on your sides of the bed.


Your Body Weight (Or Combined Body Weight If You Co-Sleep)

Most beds need to offer support to your body, so the heavier you are, the more support is needed. This is especially true for memory foam mattresses, which are supposed to contour to your body and help properly distribute its weight evenly across the bed.

Thickness is important as thicker mattresses offer more support. If you use an innerspring mattress, a thicker one will prevent discomfort and ensure that you are properly held during the night.

In memory foam mattresses, the thicker foam will ensure that you do not get swallowed up by the bed if you are heavier.

Mattresses that are too thin for your weight will likely wind up giving you lots of aches and pains, or even worse, not allowing for enough comfort to sleep through the night.
So, when you are picking a mattress, keep in mind your own weight and the weight of your partner – or revel in the extra allowance if you are a single sleeper – and how much support you personally desire.


Your Health

If you have pains, joint conditions, or similar health issues, then you may need a particular mattress firmness in order to sleep comfortably and healthily. Once again, the general rule is that thicker mattresses are softer, and thinner ones are firmer.

It can be difficult to strike a balance between these extremes, but if you are unsure, make sure you check with your doctor first and see what they recommend for you.


Your Sleeping Position

Sleeping positions determine the amount of firmness and support you need in order to sleep healthily.

Generally, medium-firm mattresses are fine for everyone universally, but you may prefer a more specialized thickness if you sleep in a particular position for most of the night.

Side sleepers have a number of different positions. If you sleep in the fetal position, with your limbs curled in towards your body so you are wrapped up tightly, then the curvature of your spine could cause back pain or other issues if you don’t have the right mattress.

It can restrict breathing, too. You will have to choose a mattress with significant pressure relief – one that is more supportive and softer, and therefore thicker.

If you are a side sleeper who sleeps in the “log” position (with your arms and legs straight) or “yearner” position (with legs straight, a slight curve to the back and arms extended), you will still need support for your shoulders and back, but less so than the fetal position sleeper.

A medium mattress with a slightly above-average thickness will serve well.

Back sleepers are said to sleep in the most healthy and comfortable position. If you sleep on your back with your arms at your side, then you can essentially choose whatever thickness is to your preference.

It should be thick enough for standard back support but it does not have to be overly bulky. If you sleep in the “starfish” position, with your arms under your pillow, then you will need a little more support for your shoulders.

Stomach sleepers face the issue of opting for one of the least healthy sleeping positions of all. It can help prevent snoring, but it can strain your neck as your head will be turned to breathe, and your back will also be bent at an angle and will not receive any support as it is facing up.

This is why many stomach sleepers face back pain. In order to counter this, you will need a very firm mattress; in other words, a thin one. You just need an inch or so of a soft comfort layer before feeling the firmness beneath.

What if you feel that you fit more than one of these? Don’t worry! Combination sleepers make up most of the world. In order to choose the right mattress for you, think of your deepest sleeping position – which position do you sleep in needs the most support?

Then choose a mattress between the deepest position’s needs and your other positions. If there is no direct in-between, skew towards the most straining position’s requirements.



Choosing the right size and thickness of a mattress is crucial to getting a good night’s sleep. It can prevent health issues and joint pain from developing, and it makes you less tired thanks to all that extra comfort.

It might seem like such a trivial matter, but without the right size mattress, you could be missing out on awesome, deeper, and happier sleep! So, don’t be afraid to test out lots of mattresses and really consider what is best for you, scientifically and personally.


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