Mattress Thickness

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Written by: Alex Savy
Last updated on

Choosing a mattress can be difficult. The market offers a wide variety of materials and dimensions, making you feel like you’re spoilt for choice. With our article, we aim to put at least one of those dilemmas to sleep (pun intended). I will show you how to choose the correct mattress thickness. At the same time, I’ll explain the inner structure of a mattress, as well as the reasons some people might need a thicker one than most.

Key Takeaways 

  • A thick mattress today is anywhere between 12 to 20 inches thick. As such, it offers a lot of support for your body.
  • The standard mattress thickness lies somewhere around 10 inches. These mattresses offer the best combination of comfort and support for most people.

What Makes a Mattress So Thick?

On the outside, a mattress looks relatively simple. On the inside, though, things can get pretty complicated.

Any mattress will contain two different layers, each serving a specific purpose. However, with some high-tech mattresses, several layers can come into play.

What Makes a Mattress So Thick

For a better understanding, we will quickly review these layers.

For me, there is no uniform standard for when a mattress is soft or hard. The mattresses that are firm in the test often turn out to be quite soft. So it all comes down to the weight, number of sleepers and how long the buyer hopes they can use it for.

Top Layer

This layer is the closest to your body and is sometimes called the comfort layer. At two to three inches thick, this layer does the job of conforming to your body. Therefore, it’s most often made from cotton, wool, or memory foam. In many cases, the bottom layer of your mattress is the same as the top layer, making it possible to flip the mattress without issue.

Base Layer

While the top layer provides immediate comfort, it’s the base layer of the mattress that supports your body. Support can come in several forms, including springs, memory foam, or latex. Hybrid mattresses use a combination of some or all of those materials. As a result, a hybrid mattress will have a base layer composed of several sub-layers.

While I advise that you direct your choice towards thick models, buyers must no not forget to study the mattress' firmness and composition. For example, as a medium sized sleeper, I usually feel out of place and uncomfortable on a thick mattress that's too firm.

Also read: Three-quarter Mattresses in Canada

Differences in Mattress Thickness

Let’s get straight to the point: what are the differences in mattress thickness, and how do they affect you, the end-user? Let’s look at a couple of standard thicknesses.

Mattresses can be categorized to ultra-thick, thick, standard, slim, and ultra-slim mattresses according to their thicknesses.

Differences in Mattress Thickness

  • Ultra-Slim Mattresses

These are up to around five inches thick. Judging by their low profile, it’s evident that ultra-slim mattresses aren’t meant for adults. Most often, you put an ultra-slim mattress in a crib. The lower thickness of this mattress type works to eliminate the possibility of your little one suffocating. This can be a severe hazard with thick, soft mattresses.

  • Slim Mattresses

Slim mattresses, typically eight inches thick, will work best for lighter individuals. A more lightweight sleeper doesn’t load a mattress as much as a heavier one does. However, a thin person will likely not have much natural cushioning to their body. That’s why slim mattresses will have a thicker comfort layer. The comfort layer can make up as much as 50% of a thin mattress’s thickness.
Apart from lighter sleepers, stomach sleepers will also benefit from a mattress with a slimmer profile. A slimmer profile means less cushioning. Therefore, a firmer surface offers better spine support when sleeping on your stomach.

For those who are like me who are average weight sleepers, our needs are similar to lighter people. I feel as comfortable by choosing the same choice of mattress as lighter people (medium firm 8 inches at least). But I think those whose weight are getting closer to 180lbs won't be comfortable on an 8 inch mattress.

  • Standard Mattresses

The standard mattress thickness lies somewhere around ten inches. If you choose a mattress of standard thickness, chances are you’ll get it right: they offer the best combination of support and comfort for most people. These mattresses are also the best choice for people who like to change their sleeping position, as they offer good support no matter what.

  • Thick Mattresses

A thick mattress will be anywhere between 12 to 20 inches thick. As such, it offers a lot of support for your body. While this kind of support is usually unnecessary for the average sleeper, some heavier individuals will see significant improvements. The weight of a heavy sleeper will overwhelm a thinner mattress, and this is where thick mattresses come in. These mattresses resist the sleeper’s weight and don’t lose shape under all that stress.
This type of mattress is also the best mattress for side sleepers. That’s because sleeping on your side puts a lot of pressure on your mattress. Thus, a thick mattress will withstand this kind of pressure without buckling under it.

  • Ultra-Thick Mattresses

Mattresses thicker than 20 inches are almost a relic from history. In the past, people used this kind of thickness to create the extra support needed for some sleepers. However, with the advent of modern mattress technology, such massive dimensions have become obsolete. I must say the only time I came across a 20 inch mattress was around 10 years ago and the user wasn't using any bed base or frame with it.


Does my bed frame play a role when choosing the thickness of my mattress?

It does: you need to integrate the two. Just like with width and length, you can’t just rely on the standard mattress thickness. Instead, you must fit the height of your new mattress to your bed frame. In general, your mattress should not stick out too much, and it should never be sunken inside the frame.

When deciding, consider the total height of your bed frame/mattress combo. You need to be able to comfortably get in and out of bed—you might risk injury otherwise (1). If you’re not sure the exact thickness needed for your bed frame, choose a mattress of average thickness, at around ten to twelve inches.

Are thicker mattresses more comfortable?

No, this is an outdated opinion. It might have been true in the past when the most effective way to add comfort and support was to pile on extra material. However, modern mattresses use modern materials, which forego the need for extra thickness.

When gauging comfort levels, you also need to be aware that what feels comfortable at first might not be the best long-term choice. As such, a thick, plush mattress may feel great when you go to bed, but it will leave your back sore in the morning.

Do thick mattresses come in a box?

The thicker the mattress, the harder it is to stuff it in a box. Therefore, any mattress in a box will be one of standard thickness or thinner.


The thickness of your mattress matters; there is no question about it. Although most people will be well off choosing a mattress of average thickness, this is not true for everyone. Weight, sleeping position, and medical issues are all factors that play a role in choosing the right thickness.

What’s your preferred mattress thickness? Do you like a thin, spartan mattress or a luxurious one fit for royalty? Let us know down in the comments!


  1. Michael W. Smith, MD (September 16, 2021). 9 Sleep Tips for Back Pain. Retrieved from

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