How Big Is A King-Size Mattress

How Big Is A King-Size Mattress

King-size mattresses have been around for quite some time. But how big are they? The mattress sizes differ widely due to the availability of different types of mattresses. This article will talk about this difference. It will also explain the inspiration for different sizes and generally what made them popular in the first place.

How Big Is A King-Size Mattress

There are three main dimensions when it comes to king-size mattresses: length, width, and height. Standard king-size mattress dimensions are 76 inches in width and 80 inches in length. Below you will also learn about the benefits of the mattress and things to consider while choosing the best bed for your home.

King Size Mattress Length

A king-size mattress is typically long enough to accommodate two people in a standard bed. The king-size mattress is the longest and widest mattress available. It is 76 inches (193 cm) long. Most king-sized mattresses are the length of a queen mattress and the width of that without the gap. The total length of a king-size bed is about six feet longer than those that only have one side or shorter than standard twin beds, so make sure you choose accordingly.

Size Is King Size Mattress

King Size Mattress Width

The width of most kingsize mattresses is around 75″ wide with an inch gap on each side, which means they can be used as an extra-long twin mattress or as one half of a full-sized bed. This type of mattress can be used in a full-size bed frame, but it works best when in a platform bed or a low-profile box spring/platform bed combo.

King Size Mattress Benefits

It’s hard to beat the comfort of a king-sized mattress. Not only does it provide more room for two people, but they’re usually more comfortable than smaller queen and twin-size mattresses. 

The bigger sizes are more popular due to their added comfort and space, plus they are also often less expensive than their smaller counterparts because they’re produced on a larger scale for big box stores and large online retailers.

King Size Mattress Benefits

The most popular feature of king-size mattresses is the extra length. Most are also more firm than queen and full-size mattresses, which provide greater support but less cushion.

As a result, they’re not ideal for people with issues with pressure points or aches. However, some king-size mattresses can be pretty firm in certain areas to help with alignment or promote deeper sleep (i.e., if you sleep on your side while pregnant).

What To Consider When Buying King Size Mattress?

The many benefits of a king-size mattress don’t come without trade-offs, and one of the biggest ones is that most are quite expensive. The good news is that there are many to choose from and it’s not hard to find one that will fit your needs.

Mattress Types

There are two main types of king-sized mattresses: innerspring mattresses and foam mattresses. Each has its own benefits and drawbacks, which you’ll need to consider when choosing which option is best for you.

Innerspring mattresses usually feature a box spring and mattress set, with an all-in-one or split box spring. These tend to be more affordable than foam options but are more likely to sag and wear down over time, especially as they age. They also aren’t very customizable. If you are going to go with an innerspring mattress, we suggest purchasing one that includes a box spring and air mattress because it will provide better support.

 King Size Mattress Types

Innerspring mattresses are typically available in all standard bed sizes, but only a few king-size options. They offer excellent pressure relief and help to align the spine properly when sleeping on your side.

Foam mattresses usually come in a one-piece version or a two-piece set, with the second piece used as either a topper or part of the foundation (some have both parts). Foam is often hypoallergenic, more durable than an innerspring mattress, and very affordable. 

They are also available in many materials, but the two most common are memory foam and latex foam. Memory foam mattresses tend to be cheaper than latex or innerspring options but not as durable or hypoallergenic. They are also not adjustable, so that you won’t find them as often at brick and mortar stores.

On the other hand, latex mattresses are more durable than memory foam and tend to be more expensive. The trade-off is that they may be harder to find due to their popularity, but they offer a softer sleeping surface that will conform better to your body.


The most basic difference between the two types of mattresses is that an innerspring is bouncier and has better edge support. In contrast, a foam mattress is softer, less bouncy, and offers better conforming support. 

This means that each one works best for different sleeping positions. Innersprings are better for back sleepers with issues like back pain or soreness, but their bounce can cause a lack of support for stomach or side sleepers who tend to sink into the mattress too much.

Newer types of foam like memory foams (hybrids) are designed to offer the best of both worlds, but they may not feel exactly like either style. It’s essential to keep in mind that the feel of a mattress is more related to how it is made than the material. For example, memory foam mattresses are thick and bouncy because they use Visco elastic memory foam.


There are many types and brands of mattresses available, and all offer different levels of firmness. If you like a softer sleeping surface, then memory foam options may be better for you.

 King Size Mattress Firmness Scala

If you like a firmer, more supportive feel, then an innerspring or latex mattress will be the best option, especially if your doctor or physical therapist has suggested you try a firmer mattress. In fact, some people find that they need to switch from plush to more firm king-size mattresses after suffering from back pain or stiffness due to injuries.

Motion Isolation

Memory foam mattresses are often considered better at isolating movement than innerspring or latex mattresses because there’s no bounce like an innerspring, so there will be less motion transfer if one person rolls over or shifts during sleep. The foam also tends to be thicker, which will help to eliminate motion transfer between partners.

 King Size Mattress Motion Isolation

On the other hand, innerspring mattresses tend to be bouncy, with coils that respond to pressure. This can make them great for motion isolation, especially if you need extra support when sleeping on your side or have back pain and need to sleep on your back.


What is the size of a King-Size Mattress mattress? 

A King-Size Mattress mattress is 76 inches wide by 80 inches long. 

What type of bed frame would fit a King-Size Mattress mattress?

A King-Size Mattress mattress is designed to fit a standard King-Size bed frame. 

How thick is a King-Size Mattress mattress?

The thickness of a King-Size Mattress mattress ranges between 10 inches and 15 inches. 

What materials are used in a King-Size mattress?

King-Size MattressFirm mattresses are usually made from foam, coil, and latex.

How heavy is a King-Size mattress?

A King-Size mattress usually weighs between 80 and 150 pounds.

What is the profile of a King-Size mattress?

The profile of a King-Size mattress varies depending on the type of mattress, but it is typically between 10 inches and 15 inches.

Does a King-Size Mattress mattress require special care?

It is recommended to rotate and flip a king-size mattress every 3-6 months to extend its lifespan.

Does a King-Size Mattress mattress require special care?

It is recommended to rotate and flip a king-size mattress every 3-6 months to extend its lifespan.

How often should a King-Size mattress be replaced?

A king-size mattress should be replaced every 8 to 10 years.

Does a manufacturer warranty cover King-Size mattresses?

Most King-Size mattresses come with a 10-year warranty.

Nick Favreau

Nick Favreau is an expert mattress writer, whose unbiased reviews and in-depth analyses of mattresses have made him a trusted source of information for those looking for quality sleep.

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