How Is Foam Density Measured?

We receive free products to review and participate in affiliate programs. See our disclosure page for more information.

When choosing the right mattress for you, there are many factors to consider. One important aspect is foam density because it impacts what kind of support you’ll get from the mattress and how long it will last. But what exactly is foam density, and how is it measured? In this article, we’ll explain everything you need to know about foam density and why it matters.

How is Foam Density Measured?

Foam density is typically measured in pounds per cubic foot (lbs/ft³) or kilograms per cubic meter (kg/m³). This measure can help you understand how supportive and long-lasting your mattress will be.

What is Foam Density?

Foam density refers to the weight of a cubic foot of foam. It measures how much material is packed into a given volume, so it’s looking at how much stuff is packed into a particular space. It’s like measuring how heavy a pillow is compared to its size. The higher the foam density, the more supportive and durable the foam will likely be.

Foam Density by Foam Type

Foams fit into three general categories when it comes to density. Here’s a breakdown on each.

High-density foam

High-density foam is known for its exceptional durability and support. It typically has a density of 5.0 lbs/ft³ or higher. This type of foam can be a good fit for those who prefer a firm mattress or experience back pain. High-density foam mattresses provide excellent pressure relief and can withstand years of use without losing their shape or support.

RELATED: 10 Best Firm Mattresses of 2024

Medium-density foam

Medium-density foam falls in the range of 3.6 to 4.9 lbs/ft³. This type of foam offers a good balance between support and comfort. It is suitable for most sleepers and is often found in mattresses that cater to a wide range of preferences. Medium-density foam provides adequate pressure relief while offering a plush and comfortable feel.

RELATED: Best Medium Firm Mattresses 2024

Low-density foam

Low-density foam has a density of less than 3.5 lbs/ft³. This type of foam is less supportive and durable compared to high-density foam. It is often used in the comfort layers of mattresses to provide a softer and more cushioning feel. Low-density foam is suitable for those who prefer a plush and sink-in sensation when lying down. While it may offer a softer feel, it tends to wear out more quickly and may lack the support needed for certain sleepers.

What Foam Density Means for Your Mattress

Now that you understand the different foam densities let’s explore what this means for your mattress. Foam density directly affects several key factors that determine your mattress’s overall comfort and performance. From pressure relief to mattress weight, foam density is an important part of creating the perfect sleep surface.

Pressure Relief

Foam density plays a significant role in providing pressure relief. Higher-density foams are more effective at evenly distributing body weight and relieving pressure points. This is particularly important for those who have joint pain or a higher body weight. Medium to high-density foams can provide good pressure relief and could even promote better spinal alignment.

RELATED: Best Mattresses for Pressure Points


The density of foam directly impacts the weight of your mattress. Higher-density foams are heavier, making moving or rotating the mattress more challenging. If you prefer a lighter mattress or anticipate the need to move or adjust it frequently, opting for a lower-density foam may be more suitable. However, remember that lower-density foams may sacrifice some durability and support.


Foam density also affects the cooling properties of your mattress. Higher-density foams tend to retain more heat and may lead to a warmer sleeping surface. If you are a hot sleeper or live in a warm climate, choosing a mattress with lower-density foam or one incorporating cooling technologies may help regulate your body temperature and provide a more comfortable sleep experience.

RELATED: Best Cooling Mattresses 2024


Foam density is closely related to the firmness level of a mattress. Higher-density foams offer a firmer feel, while lower-density foams provide a softer and more plush sensation. The choice of foam density should align with your preference for mattress firmness. If you prefer a firmer mattress, opt for higher-density foam; if you prefer a softer feel, choose lower-density foam.

RELATED: Firm vs Soft Mattress: Which Is Best for You?

Frequently Asked Questions

What density foam is best for a mattress?

The best density foam for a mattress depends on your needs and preferences. If you prefer a firm and supportive mattress, opt for high-density foam. Medium-density foam is a good choice for a balance between support and comfort. If you prefer a softer and more plush feel, low-density foam may be the right option for you. Consider factors such as your bodyweight, sleeping position, and any specific comfort requirements when deciding on the foam density for your mattress.

What does 1.8 foam density mean?

A foam density of 1.8 means that a cubic foot of foam weighs 1.8 pounds. This falls into the range of low-density foam. A mattress with 1.8 foam density will provide a soft sleep surface, but it’s likely to wear out relatively quickly.

What does 50 density foam mean?

Foam density of 50 typically refers to 50 kg/m³. This density is on the higher side, indicating a firm and supportive foam suitable for core or base layers in mattresses.

Jessie Gellings

Jessie Gellings is a freelance writer, registered nurse, and student of the American Medical Writers Association.  She specializes in supporting women-led, health-focused organizations. When she's not writing, you'll find Jessie wandering in wild places, singing, and cooking.