How is Foam Density Measured? Complete Guide

When choosing a mattress, the level of comfort that it can bring and the ability to provide you with strong support How is Foam Density Measured? Complete Guide while you sleep are often the top considerations that come to mind. While these may be the most common factors that customers look at with regards to mattress purchases, foam density is another quality that should be taken into account for polyfoam and memory foam mattresses. Density refers to the weight of the foam for one cubic foot (PCF or pounds per cubic foot) and is calculated by getting the total weight or mass of an object and then dividing this by the total number of volume units. If a foam layer has a 25 cubic feet measurement and weight 100 pounds, its density is calculated to be 4 PCF. A higher foam density measurement does not necessarily equate to increased firmness and will instead reflect the mattress’ durability and overall quality.

What are the Categories of Foam Densities?

Foam densities are broken down into these categories, with the ranges varying significantly between memory foam and polyfoam.


Material Low-Density Medium-Density High-Density
Memory Foam < 4 PCF 4– 5 PCF >5 PCF
Polyfoam <1.5 PCF 1.5 – 1.7 PCF >1.7PCF



Low-density foam has a lightweight and soft structure that makes it suitable for use as part of the comfort layers of a mattress. It is prone to easy deterioration so it will not work well when used in the core support layer of the mattress. Given its short lifespan, low-density has the lowest price range among all the foam densities. However, their structure does not trap heat, making them ideal for people who tend to sleep hot and who will benefit from sleeping on this cooler surface.


Medium-density foam offers better pressure relief compared to low-density foams. It more easily conforms to the contours of the body to prevent pressure points from building up for a comfortable and pain-free sleep experience. This density provides the right balance of firmness and softness but may become too warm since it can trap body How is Foam Density Measured? Complete Guide heat within the foam material.


High-density foams offer excellent strength and durability, and the longer lifespan is also reflected in the higher price point for this material. They respond quickly to body heat and closely conform to the body, surrounding the sleeper with a welcoming feeling all night long. This enhanced conforming ability translates to superb pressure relief for a comfortable sleep experience. However, the high-density foam has a tendency for excessive sinking and can trap body heat which can cause an intensely warm feeling.

What Mattress Qualities are Affected by Foam Density?

These are the mattress features that are directly affected by foam density.


A high-density foam offers increased durability in mattresses that allow them to be enjoyed for a long period of time with minimal wear and tear. Low-density foams exhibit lower strength and durability as they tend to sag more quickly, so this type of material will not be expected to last as long as the higher-density counterparts. Individuals who have a bulkier physique will benefit more from choosing a high-density foam material that can take on the challenge of providing ample support and comfort for a long time without premature deterioration.


The average price of the foam is affected by its density level, which is directly connected to the foam’s durability and overall quality. A high-density foam that is expected to last longer and delivers reliable performance without premature deterioration will fetch a higher price compared to a medium- or low-density foam. On the other hand, the low-density foam will have a lower price range since it tends to break down much easier compared to the higher-density counterparts.

Motion Isolation

How is Foam Density Measured? Complete Guide

Foam density also affects the ability of the foam to isolate motion, so it does not travel to other parts of the material. A foam with medium or high density works to absorb the effects of movements so they are confined to the local area, preventing sleep disturbance between partners who share the same mattress. High-density foam will make it possible for a person to continue sleeping peacefully while the other individual keeps on tossing and turning on the other side.

Conforming Ability

The conforming abilities of foam are influenced by the density, but they can also be affected by the weight of the individual sleeping on the surface. The low-density foam will provide greater benefits to people with lighter body structures who will sink in slightly in the softer material, which will work to prevent pressure spots from developing. Heavier sleepers, on the other hand, may find that sleeping on the low-density foam can be uncomfortable since they will sink in more deeply. This will cause incorrect spinal alignment that can result in body pains especially when sleeping for a long period of time.

Heat Retention

Heat retention goes up along with the density of the foam. The higher the foam density, the greater its capacity to retain heat, which can bring a great deal of discomfort with an excessively warm feeling that can disrupt what should be a restful night of sleep. High-density foam is not recommended for people who often feel hot when sleeping for long hours because the material allows body heat to accumulate and be trapped within. Foams, in general, are not ideal choices for people who tend to sleep warm, but a low-density foam may bring more comfort because it retains less heat compared to a high-density material.


Mattresses that are made purely of foam are much heavier compared to hybrid or innerspring mattresses. The foam density also increases with the weight of the foam, with the low-density foam being significantly lighter and much easier to carry around and maneuver compared to the medium- and high-density foam material.

Pressure Relief

Foam density levels directly affect the conforming capabilities of the mattress, with a higher density providing How is Foam Density Measured? Complete Guide greater conforming that allows the body to sink in gently into the surface so that pressure points are prevented from building up to ensure a comfortable sleep experience throughout the night. Individuals who have a lighter body structure will enjoy ample pressure relief when using low- or medium-density foam, while heavier body structures can experience more comfort when sleeping on high-density foam.


Foam density is an important thing to consider when you are planning to purchase a mattress. Knowing how to compute the foam density and how each level or category affects the mattress’ features will help you in making the best product choice. The information can make it easier for you to determine which material to choose depending on the qualities that you find most important in a mattress. It should be noted the density levels and their effects on the mattress qualities may vary depending on the weight of the mattress occupants, so this should always be taken into consideration.

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