How Thick Should a Mattress Be?

Mattress Thickness Chart

Because we spend about a third of our lives sleeping, it is important to choose a mattress that is comfortable, durable, and promotes healthy spinal alignment. 

Mattresses come in a variety of thicknesses to accommodate varying needs and preferences. To determine which might work for you, consider bed height preferences, mobility issues, body weight, and sleeping position. If you sleep with a partner, you should also factor in their needs to find a comfortable solution for both of you.

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How to Choose a Mattress Thickness Level 

There is no one-size-fits-all mattress. The trick to finding the best mattress with the right height for you is understanding the thickness options and who they work best for.

Low-profile mattresses range from 4 to 8 inches thick. They are most common in situations where a thicker model just won’t fit, such as in bunk beds, trundle beds, and Murphy beds. Children can often sleep comfortably on them. However, we don’t generally recommend low-profile models for adults because they tend to be less supportive, with insufficient pressure relief.

Slim mattresses are 8 to 10 inches thick. While this is thinner than average, it’s thick enough to accommodate many adults. Slim models may be ideal for sleepers who struggle to get into or out of a low bed, such as shorter adults and those with mobility issues. Most children can also sleep comfortably on this thickness.

The standard thickness of 10 to 12 inches is adequate for most average-sized adults. At this height, most models have substantial comfort and support layers. Since this profile is so common, shoppers can select from a wide range of materials, price-points, and firmnesses. 

Thick mattresses — also known as deep mattresses — are 12 to 14 inches tall. They typically have a generous comfort layer that offers more pressure relief and contouring while still containing a considerable support core. Since the deeper comfort system leaves more room for a sleeper to sink in, side sleepers and individuals over 230 pounds often prefer thick mattresses. These models also tend to be more durable than average. 

Extra-thick mattresses are at least 14 inches tall. Some reach upward of 20 inches. Combining plush comfort layers and a thick support core generally creates a highly durable mattress well suited to sleepers over 230 pounds. However, extremely high-profile models are usually pricier, heavier, and more difficult to set up.

Sleeping Position

Your sleep position influences how much pressure you put on the bed and where that pressure is concentrated. Therefore, it also affects how thick your mattress should be. 

Side Sleepers: Side sleepers put more pressure on their shoulders and hips, so they generally need a thicker mattress for adequate pressure relief. Most prefer a model that’s at least 12 inches thick with a substantial comfort layer. A mattress that is too thin is unlikely to let a side sleeper’s shoulders and hips sink in enough, which can lead to pressure buildup and poor posture. 

Back Sleepers: Back sleeping often leaves a gap between the lower back and the mattress, which can create extra tension in the lumbar area. A mattress between 10 and 12 inches thick that provides some contouring without sagging can help support the natural curvature of a back sleeper’s lower spine.

Stomach Sleepers: Stomach sleepers are vulnerable to lower back strain if their midsections sink in too deeply. They should typically look for a mattress around 10 inches thick with enough support to prevent their spines from bending into a U-shape. A taller model may also be suitable if it has a relatively thin comfort system.

Combination Sleepers: As the name implies, combination sleepers change positions throughout the night, meaning they need a versatile mattress that can accommodate different positions. In general, a 12-inch mattress should have a good balance of cradling and support.

Body Weight

Body weight is just as important as sleep position when choosing a mattress thickness. Sleepers who weigh more sink into a mattress more deeply than lighter individuals and generally need the added support of a thicker mattress.

Sleepers Under 130 Pounds: Thin mattresses often feel too firm for sleepers under 130 pounds. They are traditionally more comfortable on a model at least 12 inches thick with a generous comfort system that offers significant pressure relief and contouring. However, young children can easily use thinner foam mattresses, such as those commonly found in bunk beds.

Sleepers Between 130 and 230 Pounds: This weight range encompasses most average-sized adults. A mattress that is 10 to 12 inches thick is usually sufficient. However, your sleeping position and the mattress materials may also influence the ideal thickness.

Sleepers Over 230 Pounds: Because they sink in more deeply, sleepers over 230 pounds generally favor a mattress at least 12 to 14 inches thick. They typically need a thicker comfort system and a sturdy support core to contour to their bodies without sagging.

Number of Sleepers

If you sleep with a partner or a child, finding a mattress thickness that suits both of you is inherently more complicated. Couples need a mattress that’s thick enough to support their combined weights and durable enough to last.

You should also consider your preferred sleeping positions. Anyone sharing a bed should look for a mattress at least 10 inches thick. Thinner models are more likely to sag under your combined weight. Sleep partners who both weigh over 230 pounds often need an extra-thick mattress for sufficient support.

Bed Base Height

Consider the height of your bed base when shopping for a mattress. If you’re using a bed frame and a box spring, an extra-thick mattress may be challenging to climb into. At the same time, a thin mattress paired with a low-rise platform bed may seem too close to the ground. 

You should be able to sit comfortably on the edge of the bed with your feet resting on the ground. This makes getting in and out of bed much easier, especially for those with limited mobility. Keep in mind that many mattresses and bed frames don’t require a box spring.

What Determines Mattress Thickness?

Mattress thickness is determined primarily by the heights of the bed’s main components: the comfort system and the support core. 

The comfort system consists of the layer or layers closest to your body. It’s the softest part of the bed designed to provide pressure relief, contouring, and motion isolation. Most comfort layers are 1 to 4 inches thick. Thinner comfort layers are more common in firmer models, while softer options usually have thicker comfort systems. 

The support core is at the base of the mattress and generally comprises half to two-thirds of the thickness. It provides overall support and prevents sleepers from sinking too far into the surface. In general, a thicker support core makes a mattress more durable.

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