Memory Foam

Memory foam is a type of polyurethane foam known for its soft, energy-absorbing feel. It moulds to the shape of the body under pressure and slowly returns to its original shape when the pressure is removed, which is why it is widely used in mattresses, pillows and other comfort products.

Memory foam was developed in the 1960s under a NASA Ames Research Center programme to improve the safety of aircraft seat cushions. Its open-cell structure reacts to body heat and pressure, allowing it to mould to the body and then gradually recover its shape, making it well suited to products that need both comfort and support.

Quick Reference: Types of Memory Foam

Properties of Memory Foam

Memory foam is viscoelastic: it responds to pressure slowly and recovers its shape gradually rather than springing back. This allows it to contour to the body and spread weight evenly across the surface, which is why memory foam mattresses and pillows feel so comfortable.

Memory foam is also temperature-sensitive. It becomes softer and more pliable when warmed by body heat, helping it to mould to the body. This can also be a downside, as some people find memory foam products too warm, especially in hot weather.

Density and Firmness

The density of memory foam is the amount of foam per unit volume, measured in kg/m³ or pounds per cubic foot. Higher-density memory foams are generally more durable and supportive, but can be more expensive. See our guide to foam density for more.

Firmness is a separate measurement, often given as ILD (Indentation Load Deflection): the force needed to compress a 4-inch-thick foam sample by 25%. Higher ILD ratings indicate firmer foams and lower ratings softer foams. Density and firmness together determine how a memory foam feels and performs. Learn more in our guide to foam compression.

Open-Cell Structure

Memory foam has an open-cell structure, meaning its cells are interconnected, unlike closed-cell foam, where the cells are sealed. This allows air to circulate through the foam, which can help to regulate temperature.

Over time, the cell structure of memory foam can gradually break down, particularly in lower-density foams, causing it to lose some of its shape and support. Choosing a higher-density foam helps to extend its life; see our guide to foam durability.

Uses of Memory Foam

Memory foam is most commonly used in mattresses and pillows, where it contours to the body to provide personalised support and reduce pressure points. This can help to improve sleep quality and may help to ease back and neck discomfort.

It is also used in shoe insoles, seat cushions and pet beds, and in healthcare, where it is used in wheelchair seat cushions to help reduce the risk of pressure sores and in hospital mattresses to improve comfort for long-term patients.

Memory Foam Mattresses

Memory foam mattresses are popular because they contour to the body, distribute weight evenly and reduce pressure points. Their dense structure can also be less hospitable to dust mites than some other mattress types.

However, they can be expensive and can retain heat, making them uncomfortable for people who sleep hot. Some people also dislike the sinking feeling of memory foam and prefer the bounce of a sprung mattress.

Memory Foam Pillows

Memory foam pillows contour to the head and neck, providing personalised support and reducing pressure points, which can help to improve sleep quality.

Like memory foam mattresses, they can retain heat, and some people find them too firm and prefer the softness of down or fibre-filled pillows.

Types of Memory Foam

The main types are traditional, gel-infused and plant-based memory foam. Traditional memory foam is the most common, known for its soft, supportive feel and ability to contour to the body, although it can retain heat.

Gel-Infused Memory Foam

Gel-infused memory foam has gel particles or liquid gel mixed into the foam to help draw heat away from the body, making it feel cooler. It is often used in mattresses and pillows for people who sleep hot.

The gel can make the foam feel firmer, which some people dislike, and its cooling effect can reduce over time.

Plant-Based Memory Foam

Plant-based memory foam replaces some of the petroleum-based ingredients with plant-based oils, making it a more environmentally friendly option. Like traditional memory foam, it has an open-cell structure that allows air to flow through.

It can be more expensive than traditional memory foam, and its feel can differ, so some people may prefer one over the other.

Memory Foam vs Other Foams

Other foams used in mattresses and furniture include standard polyurethane foam, latex foam and high-resilience (HR) foam, each with its own properties and uses.

• Standard polyurethane foam: Common in mattresses and furniture. It is generally less expensive than memory foam, and lower-density grades are less durable.
• Latex foam: Made from rubber tree sap (or synthetic latex). It is typically more durable and responsive than memory foam, but more expensive.
• High-resilience (HR) foam: A polyurethane foam that is more durable and supportive than standard polyurethane foam, with a springier, more responsive feel than memory foam. See our guide to foam resilience.

Memory Foam vs Latex Foam

Memory foam has a soft, contouring feel, while latex foam has a bouncy, responsive feel. Memory foam moulds closely to the body and relieves pressure points but can retain heat. Latex foam is more breathable and stays cooler, but it does not contour to the body as closely, which some people find less comfortable.

Memory Foam vs Polyurethane Foam

Memory foam and standard polyurethane foam are both types of polyurethane, but they have different properties and uses. Standard polyurethane foam is a common, lower-cost choice for furniture cushions and budget mattresses. Good-quality memory foam offers more contouring support and can last well, making it a popular choice for mattresses and pillows, although it costs more and can retain heat.

Choosing the Right Memory Foam for Your Project

• If you sleep hot: Consider gel-infused memory foam, or a more breathable alternative such as latex.
• For long-lasting support: Choose a higher-density memory foam.
• For a more environmentally friendly option: Consider plant-based memory foam.
• If you prefer a bouncier feel: Latex or HR foam may suit you better than memory foam.

Final Thoughts

Memory foam is known for its comfort and pressure-relieving support, and is used in everything from mattresses and pillows to insoles and seat cushions. Its main downsides are heat retention and, in lower-density foams, reduced durability. Understanding the differences between traditional, gel-infused and plant-based memory foam will help you choose the right option for your needs.

Explore Related Foam Guides

Continue exploring foam types and properties across our technical glossary:

• Latex Foam: Natural and synthetic latex for mattresses and cushions.
• Polyurethane Foam: The most widely used foam in furniture and bedding.
• Foam Density: How mass per cubic metre affects support and lifespan.
• Foam Compression: How firmness ratings such as ILD are measured.
• Foam Cushioning: How different foams provide comfort and support.
• Cushion Fillings: Comparing foam, fibre and other cushion fillings.

Looking for Memory Foam Cut to Size?

Whether you need a memory foam topper, seat pad or cushion insert, the Foam & Covers team can help you choose the right foam and cut it precisely to your measurements.

Contact Our Foam Specialists or Order Custom Cut Foam Online .