Memory foam was initially developed by NASA in the 1970s to provide supportive cushioning for astronauts during launch of high-powered spacecraft. It is a type of polyurethane foam and may be more specially referred to as viscoelastic polyurethane foam. After this material was released to the public, it was modified and adapted into many commercial applications, including mattresses.
The key feature of memory foam is that it is viscoelastic, which means that it changes shape when pressure is applied and then returns back to its original shape when the pressure is removed. This compression process is also affected by temperature because memory foam becomes more flexible as it warms up.
For mattresses, this means that memory foam can provide an excellent balance of support and comfort. Because it contours to the individual, memory foam offers support to fit your specific body shape and size.
While these mattresses are popular with all types of sleepers, they are often a top choice for side sleepers and consumers with back pain or who otherwise want to avoid pressure points during sleep. You can jump to our recommendations for the top memory foam mattresses here, or you can scroll to read our guide for all the ins-and-outs of memory foam.
Types of Memory Foam Mattresses
While all memory foam mattresses include viscoelastic foam, most mattresses are made up of layers of different types of foam. The thickness and composition of these foam layers contributes to the overall feel of the mattress with the goal of striking the right mix of both support and comfort. Usually only the top few inches of the mattress are composed of actual memory foam.
Memory foam mattresses may have other features included in their construction. For example, gel memory foam mattresses include gel-filled beads within the foam layers. This is designed to help keep the mattress cool, although some research suggests that gel-infused mattresses do not stay any cooler than standard memory foam mattresses.
Copper-infused memory foam is another new innovation that incorporates copper-filled beads into the foam layers with the goal of keeping the mattress cool. Copper has also long been promoted as a remedy for joint pain and circulation issues; however, the evidence to support these claims is limited.
The Feel of Memory Foam
Memory foam mattresses are known for contouring to the body of the sleeper. Because the foam compresses based on the amount of pressure applied, it often feels more responsive than other types of mattresses. This can be described in different ways. Some people refer to it as a feeling of a “hug” from the mattress. Other people describe this as a feeling of sinking into the bed, although how much this happens depends on the firmness of the memory foam.
The popularity of memory foam stems from the fact that its responsiveness allows it to feel “just right” for each part of the body. This can help make sure that a person has adequate full-body support, which can help maintain proper spinal alignment and prevent back pain.
Benefits of a Memory Foam Mattress
The biggest benefit of memory foam is that it can relieve pressure points in the body. Because of the foam’s ability to adjust to the size and sleeping position of each person, it provides a high level of support that can reduce the risk of joint or muscle pain, including back pain. In addition to being supportive, many people find the feel of memory foam to be extremely comfortable because of its contouring effect.
Another benefit of memory foam is motion isolation. This means that pressure on one part of the foam does not affect the compression of the foam on other parts of the mattress. For couples, this can reduce the disruption to the other sleeper when one person gets in and out of bed or moves around in bed. A famous example of motion isolation is the wine glass test, in which a wine glass positioned on memory foam is not affected by pressure elsewhere on the bed (see below for Koala Mattress’ clever spin on it).
Memory foam mattresses can also be compressed for shipping, which allows for many of these mattresses to be purchased online or without needing the use of a truck. Once the mattress is unboxed and unwrapped, the foam fills out to reach its full shape.
Drawbacks of a Memory Foam Mattress
While there are many benefits to memory foam, these aren’t the best mattresses for everyone because of a few drawbacks.
One downside of memory foam is heat retention. It is common for people to describe memory foam mattresses as “sleeping hot.” This can be a result of the low breathability of memory foam. It can also be a consequence of the hug of the mattress as it contours to the body. The amount of heat retention varies based on the composition and thickness of the foam. On balance, though, all memory foam mattresses retain more heat than innerspring or hybrid mattresses.
Another complaint about memory foam is its chemical smell. This issue is also referred to as off-gassing. Particles known as volatile organic compounds (VOCs) are formed during the manufacturing of most memory foams, and these particles are released when the mattress is removed from its packaging. While some people may have a strong immediate reaction to the smell, there is no evidence that it is harmful. Thicker mattresses may have a greater smell while mattresses made with plant-based materials usually have little or no off-gassing. The smell almost always goes away within a few days after unpackaging the mattress.
Another drawback for memory foam is that it isn’t the ideal material for sex. Though it varies for every couple, some find that the contouring effect can give a feeling of “fighting” the bed, and the lack of bounce or responsiveness may be a distraction during sex.
Finding a Quality Memory Foam Mattress
There are many different types, styles, and brands of memory foam mattresses. It is important to keep in mind that there is no one perfect memory foam mattress for everyone. But knowing what to look for when shopping for a memory foam mattress can help make sure that you choose the best option for you.
Two important factors to consider are density and load-deflection. Density is measured in pounds per cubic foot and helps indicate how well the mattress is likely to support your body weight. Most of the memory foam mattresses on the market have a density range of 2.5 to 8 pounds per cubic foot for the memory foam comfort layer. A common benchmark for a quality memory foam mattress is a density of 4-5 pounds per cubic foot. Lower-density memory foams may not provide adequate support and may degrade more quickly. Higher-density memory foam mattresses are often perceived by sleepers as too firm and also tend to be significantly more expensive.
Indentation load-deflection (ILD) is another way of assessing the firmness of a memory foam mattress. It is determined based on how much pressure must be applied to create a four inch indentation in the mattress. The higher the ILD number, the firmer the mattress. ILD may be expressed as a range because it can be influenced by other factors such as the temperature of the room where the mattress is kept. Memory foam mattresses typically have an ILD between 8 and 20 for the memory foam comfort layer. As a general rule, look for a memory foam mattress with an ILD of at least 10.
There are several other factors to consider when shopping for the best memory foam mattress for you:
- Cooling elements. Because of the contouring effect of memory foam, some people find these mattresses to be too warm. Cooling features, such as gel-infused and copper-infused foams, are designed to help reduce this effect, although the extent to which they work is up for debate.
- Thickness of the top memory foam layer. Not all foam mattresses have the same thickness of the top layer of true memory foam. A thicker top layer may provide more support to certain sleepers, especially people who are heavier or otherwise feel they need extra contouring and support.
- Mattress cover. The top cover, which goes over the memory foam layer, can be made with various types of material and thickness levels. This may affect the feel of the mattress for you as well as its heat retention properties. If the cover is too thick, it may affect the responsiveness of the memory foam layer. Some thicker covers may also exacerbate heat retention issues.
- Materials and chemicals used to make the mattress. Many foams are produced with flame retardants or with other chemicals. These are generally regarded as safe, but some consumers prefer a mattress made with plant-based materials or one with foam certified by an organization like CertiPUR-US.
Lifespan of a Memory Foam Mattress
The durability of a memory foam mattress can depend on the thickness and density of the foam and the quality of the materials used to build the mattress. With regular use, most memory foam mattresses can be expected to last for at least 5 years and often much longer. In order to get the longest lifespan for your memory foam mattress, look carefully at the materials and the composition of the mattress. Make sure to inspect other parts of the workmanship such as the stitching on the cover and on any seams.
In addition, look for a robust warranty for your mattress. While the length of the warranty is important, also make sure to carefully read what the warranty covers. For example, try to find a mattress with a warranty that covers sagging of the foam and damage to the cover. The warranty should include clear terms for how the manufacturer handles warranty claims including turnaround time, shipping costs, and mattress replacement.
Cost of a Memory Foam Mattress
Like most products, there’s a broad price range for memory foam mattresses. On the extreme low end, some memory foam mattresses can be found for $300 while luxury mattresses can easily cost over $3,000. Ultimately, you can find an excellent memory foam mattress for between $800 and $1,000.
Questions to Ask When Buying a Memory Foam Mattress
When buying a memory foam mattress either online or in the store, make sure that you know and are comfortable with the answers to these questions:
- What is the composition of the foam layers?
- What is the density and firmness of the foam?
- Will this mattress work well given my preferred sleep position?
- If you share the bed with a partner: will this mattress be comfortable for both of us?
- If you are concerned about off-gassing: is the bed constructed with materials that reduce the amount of off-gassing?
- Is there a trial period to test out the mattress? If so, what is the return policy?
- What are the terms of the manufacturer’s warranty?
Our Favorite Memory Foam Mattresses of 2017
When considering foam mattresses, we included two additional criteria for our methodology. The first is free shipping and the second is a sleep trial with free returns. One of the downsides of buying online is that you can’t get a feel for the mattress until it is delivered. We only considered sellers who included a free sleep trial that comes with free pickup or returns if the mattress isn’t the right fit for you.
For all-foam mattresses, the quality of the foam is one of the most important factors in determining how comfortable and how durable the mattress will be. As a result, we only considered mattresses that met certain characteristics:
A top layer (“comfort layer”) with at least 3.5 pounds per cubic foot (pcf) of density. This density level helps ensure that you don’t sink too deeply into the mattress, which can cause spinal misalignment and a feeling of overheating while asleep.
Support layers made up of foam with a density of at least 1.8 pcf. Some manufacturers install high-quality comfort layers but then cut corners on the support layers. This threatens the overall support level of the bed and can threaten the bed’s durability, so we ruled out any mattresses with weak support foam.
Our choice for the top foam-only mattress of 2016 is the Leesa Mattress. The Leesa is one of the most popular foam mattresses on the market and for good reason as it boasts a number of major features:
- Excellent comfort layer: the top layer of the Leesa mattress is made with Avena foam that has a density of 3.6 pcf. This foam material provides the support associated with traditional “memory foam” but with slightly more spring-back. This prevents sinking too deeply into the mattress, which can create a host of problems ranging from “sleeping hot” to poor spinal positioning.
- Strong supporting foam layers: the Leesa comfort layer is buttressed by a 2 inch layer of 3 pcf memory foam and a 6 inch layer of 1.8 pcf support foam. These foam layers boost the Leesa’s edge support relative to most memory foam. They also contribute to a more solid and durable mattress overall.
- 100 night sleep trial: Leesa allows you to try out the mattress for 100 nights with risk-free, no-cost returns.
Free delivery: delivery is included in the price, and the compressed mattress can be delivered in a box to your front door in just a matter of days.
- Company reputation and principles: Leesa has an A rating from the Better Business Bureau (BBB) and is set up as a B-corp, which means they include a social and environmental focus as part of their business principles. Leesa donates one mattress to people in need for every 10 that they sell.
Potential concerns for the Leesa mattress:
- Less contouring: the Leesa does not hug or contour to the body to the same extent as some traditional memory foam. Sleepers looking for maximum sink and hug may want to choose a different mattress.
Honorable Mention for Best All-Foam Mattress
- Loom and Leaf: this popular direct-to-consumer mattress includes a unique medical grade cooling gel on top of high density memory foam and support foam. It’s the quality of a tempurpedic mattress at a much more affordable price point.
- Nest Bedding Alexander Signature Series: this mattress features a number of foam layers and a plush quilted top. It is a solid choice for people who want a taller mattress or one with more hug from their mattress.