What Is Memory Foam (and How Does it Work)?

June 9, 2020 | Casper Editorial Team

Memory foam is a synthetic material known for its use in mattresses (although it’s also used in bedding, shoes, and furniture). It’s soft, durable and heat-wicking abilities, provide support for aching joints and have made it popular with sleepers of all body types and sleep styles.
You may recognize memory foam from the notable 90s commercials that demonstrated memory foam’s ability to absorb impact, featuring actors jumping on the mattresses next to unspilled glasses of wine. The foam mattress’ ability to evenly distribute weight made it very popular – especially with restless sleepers – and its reputation continued to grow. Research and Markets reported that the memory foam mattress and bedding markets will break $8 billion in the United States by 2023.
If you’re thinking about making a switch to a memory foam mattress, read further to learn about the benefits and drawbacks, types of mattresses, foam densities, and materials used. Our comprehensive guide will teach you everything that you need to know about memory foam.
A block of memory phone next to this fact: "Memory foam was originally called 'slow spring back foam' due to its ability to match the pressure against it and retake its original form"

What Are the Benefits of a Memory Foam Mattress?

There are numerous benefits to sleeping on a memory foam mattress. Multiple mattress review and medical websites have linked memory foam mattresses with good sleeping posture and reduced back pain. If you’re unsure about making the switch, take a look at the perks it provides:

Regardless of all the benefits, some shoppers prefer the sturdy feel of an innerspring mattress. A hybrid mattress blends together memory foam and pocket-wrapped coils for the best of both worlds.

What Are the Disadvantages of a Memory Foam Mattress?

Not all memory foam mattresses are created equal, and just as there are lots of benefits, there are drawbacks to traditional memory foam mattresses:

  • Some memory foam can be heavier than traditional spring mattresses (here are Casper’s weight specifications).
  • Temporarily leak off-gassing chemical odors, due to volatile organic compounds (VOCs). They are not uncommon and often found indoors and in household products. Exposure to high levels of VOCs can cause eye, nose and throat irritation when inhaled.
  • Can begin to dip and sag over time, losing their recoil.

Despite the disadvantages of some foam mattresses, sleepers of all styles will experience comfort and support with Casper’s foam mattresses. Comprised of four layers, the Casper Original Mattress combines premium foams, including a breathable open-cell foam and a high-density memory foam, for a soft and supportive mattress that sleeps cools. This has positioned Casper as a leader of innovation within the sleep industry.

How Does Memory Foam Work?

Memory foam uses the body’s heat to soften and mold to its contours, wrapping the sleeper in a cushion of support and relaxation. Memory foam mattresses are composed of multiple layers of foam that range in size and thickness. The bottom layer is made up of polyurethane foam, followed by a transitional layer and several layers of memory foam on top.
The firmness of a memory foam mattress is measured in indentation load deflection (ILD). This refers to the weight required to make an indention in the mattress. Memory foam densities equal the firmness of the mattress, while thickness is the actual height of the mattress.
A metal disc showing how far it sinks into a block of foam next to this fact: "Indentation load deflection, or ILD, measures a mattress's firmness; the lower the ILD, the softer the mattress".
Memory foam densities range from low (1.5 to 3 pounds per cubic foot) to medium (4 to 5 pounds per cubic foot) to high (6 to 8 pounds per cubic foot). A heavier mattress has higher-density memory foam.
In some cases, mattresses can weigh more than 100 pounds. Regardless of weight, the density accounts for the support, durability and longevity of the mattress. If you’re looking for more support, a medium- to high-density foam mattress is your sleeping chariot of choice.
Don’t let the sleep jargon scare you. We’ll touch on the differences between traditional, gel pod and open-cell foam mattresses, their features and the best sleep styles for each mattress type.
A hand pressing into a memory foam mattress next to this fact: "Memory foam uses the body's heat to soften and mold to the contours, wrapping the sleeper in a cushion of support and relaxation."

What Are the Different Types of Memory Foam Mattresses?

There are three types of foam mattresses: traditional memory foam, open-cell, and foam with gel pods. Each has unique features equipped for every sleeper. The Casper mattress unites high-density memory foam and breathable open-cell foam for that signature “just right” feel.
Traditional Memory Foam Mattresses
The earliest version of the trio, the traditional memory foam mattress, is what comes to mind when most people think of 1990s late night memory foam commercials. The polyurethane by-product provides the perfect sleeping experience, compressing around body curves during sleep.
A diagram showing the composition of a memory foam with these facts: "1. In the deep layer: Closed-cell structure that traps heat. 2. In the top layer: Polyurethane foam conforms to the body during sleep."
While it’s often compared to sleeping on a pillow, some users complain of the mattresses retaining high levels of heat. This is due to the closed-cell structures that trap heat. People that sleep hot or live in warmer climates and can’t find comfort on traditional foam mattresses, often opt for the gel pod or open-cell models.
Open-Cell Memory Foam
Open-cell memory foam mattresses are like a sponge, constructed from millions of small passages. These small tunnels allow air to circulate and heat to escape when weight is applied.
Diagram of an open-cell memory foam mattress with these facts: "1. Top layer: Less dense, softer than traditional. 2. Middle layer: 'open cells' allow air movement throughout the mattress."
Foam Mattresses with Gel Pods
Foam mattresses with gel pods are regarded as more advanced mattresses when compared to traditional memory foam and open-cell foam. Gel pods are incorporated into the top layer for progressive comfort and full body support.
Diagram of a gel pod foam mattress with these facts: "1. Middle layer: Gel pods add extra support. 2. Top layer: Has natural bounce to pop back to its original shape."

What Is Off-Gassing in a Mattress?

Off-gassing is a chemical odor that comes from the breakdown of volatile organic compounds (VOCs) that are used in the production of foam mattresses. The chemicals that make up VOCs (chlorofluorocarbons (CFCs), formaldehyde, benzene, methylene chloride) are inactive after the mattress is produced.
Polybrominated diphenyl ether (PBDE) is one of the most discussed chemicals used in the development of memory foam mattresses. It’s a chemical compound that’s used as a flame retardant in furniture, adhesives, carpets and other products. When expelled from a foam mattress they can cause headaches, eye, sinus and respiratory irritation. Should you encounter a smell coming from your new foam mattress, let it air out in a well ventilated room for 48 to 72 hours.
Our mattress foams are CertiPUR-US® certified. They are environmentally safe, free from PBDEs and low in VOCs emissions.

Are Memory Foam Mattresses Eco-Friendly?

Today, many consumers view utilizing organic and eco-friendly materials as a chief concern. From clothing and cleaning products to vehicles and bedding, the materials we interact with on a daily basis are critical to the health of humans and the environment.
In response to these concerns, many mattress companies like Casper® have environmental certifications, eco-friendly mattresses that are made from plants, cotton, wool and other all-natural products. This ensures that the mattresses aren’t made from harsh materials, decrease the carbon footprint and meet national safety standards such as CertiPUR-US and GREENGUARD certifications.
Can you put a price tag on a quality night’s sleep? When purchasing a memory foam mattress anticipated comfort, durability and eco-friendliness are at the top of the list.

How Much Does a Memory Foam Mattress Cost?

Memory foam mattress prices range in low, middle and high tiers. The average cost of a queen-size mattress is $860. A Casper foam mattress starts at $249 and the Casper Queen memory foam mattress, our most popular mattress size, is $449.
For some, sleeping on a memory foam mattress is like sleeping in another world. It’s a big decision to purchase a new bed, especially one that you’re going to be sleeping on for the next 10 to 15 years. This big commitment doesn’t come without its rewards, so get ready for a good night’s sleep. Before purchasing a memory foam mattress, do your research, speak with a sleep specialist and take time to understand what features matter the most to you.