We have compiled the industry's most extensive mattress glossary to help you better understand this increasingly complex space. Getting a good night's sleep isn't always simple, and your mattress can have a lot to do with it. There are many factors to consider in shopping for a mattress, and understanding the terminology can help you to make the right decision. Whether you're looking online or in brick and mortar stores, we recommend familiarizing yourself with these concepts before you start your search.

A B C D E F G H I K L M N O P Q R S T U V W

Adjustable Base Compatibility

The ability of a mattress to be bent when used with an adjustable bed.

Adjustable Bed

A base that can be raised or lowered, and often the back can be raised to a 45-degree angle, and/or the legs can be elevated. These beds are chosen by people who like to read in bed without having to prop up lots of pillows, and are also used in hospitals and long-term care facilities.

Air Bed

A bed filled with air instead of traditional innerspring coils or other options such as foam, gel, or a hybrid. They are convenient for traveling as these beds can be deflated and rolled up, but are not good for support and aren't recommended for long-term use.

Air Chamber

The sections inside an air bed that hold the air.

Alaska King

The largest mattress, measuring 9' by 9'.

Alberta King

A mattress measuring 8' by 8'.

Allergen

Something that causes an allergic reaction.

Anti-microbial

Material that has been treated to prevent the growth of mold, bacteria, fungus, and dust mites.

Articulation

An adjustable bed with "1-point articulation" folds in one spot (usually so the back will rise), "2-point articulation" will fold in 2 spots (usually the back and the legs will rise).

Avena Foam

A patented foam that has some of the properties of latex (cool and responsive) but is more durable.

Bamboo Fabric

A soft, breathable fabric that's anti-microbial and wicks away sweat and moisture.

Batting

Also known as wadding, it's the filling that makes quilts warm and heavy. It can be made from cotton, polyester, wool, or bamboo.

Bed Frame

Made of wood or metal, this is what raises the bed off the floor and gives it support. If your mattress seems to lack support, it may be that your bed frame is bent or part of it is broken, which can damage your mattress.

Biodegradable

A term applied to a product that will break down into non-harmful organic matter. Note that there's not yet a legal definition for this term and some products are mislabeled.

Bladder

A chamber that holds water in a waterbed.

Blended Latex

A combination of synthetic and natural latex that provides both elasticity (from natural latex) and consistent quality (from synthetic latex).

Bonnell Coil

Hourglass-shaped springs that provide support in innerspring mattresses.

Border Wire

A wire that surrounds the perimeter of a box spring or innerspring mattress. It helps the mattress maintain its shape and improves durability by connecting to the outer part of the coils.

Box Spring

A foundation that goes underneath a mattress to help give support to a mattress. A box spring is made of heavy coils inside of a wood frame with little to no padding on the top.

Boxed Delivery

When a foam mattress is delivered in a medium-size box and you have to allow up to 3 days for the mattress to sit outside of the box to decompress and reach its intended size.

Bunkie Board

A thin, stiff board that's placed under a mattress as opposed to a box spring.

California King

A mattress that measures 72" wide by 84" long, slightly narrower and longer than a standard King.

California Queen

A mattress that measures 60" wide by 84" long, which is a little longer than a standard Queen.

Certified Organic

Normally for a product to qualify as USDA Organic, at least 95% of the materials need to be organic and to be processed without potentially harmful chemicals. As of now, the USDA won't certify mattresses as organic, but a mattress can be certified by GOTS (Global Organic Textile Standards).

Coils

Spirals of wires inside an innerspring mattress that give it both support and softness. There are variations in shape, size, and gauge creating different levels of support and feel to a mattress.

Coil-on-coil

Two layers of coils on top of each other that improve comfort and support. These mattresses are more expensive.

Comfort Guarantee

This usually means that you can return a mattress for another one, but not get a refund.

Comfort Layers

The upper few inches of a mattress that help give a softer feel to a mattress.

Continuous Coil

An innerspring mattress design where s-shaped springs form a single wire, creating a stable and durable mattress. It's the least expensive of all the innerspring coil designs.

Contoured Mattress

A mattress that provides a mixture of softness and pressure-relieving support by conforming to your body.

Convoluted Foam

Foam shaped similar to an egg carton, giving additional surface cushioning.

Core

The support layer of a mattress such as innerspring or foam.

Cotton

A natural fiber used in making some mattresses.

Cotton Felt

A narrow width roll of uncompressed carded cotton, or cotton and wool mix, sandwiched between thin paper layers.

Cover

The fabric that encases a mattress.

Crib Mattress

A mattress designed for use in a baby crib that normally has a water-resistant cover and is firm.

Crown

When a mattress lifts up in the center.

Cushioning

The layers of latex, foam, felt, polyester, cotton, or other material between the insulation and the quilting of an innerspring mattress.

Cushioning Depth

The measurement of how much a person sinks into the mattress.

Damask

A woven fabric used to upholster a mattress, also known as ticking. Damask is usually made from cotton, rayon, or linen, and gives a classic woven look. Designs usually feature motifs or leaves, vines, or flowers.

Daybed

Furniture that functions as both a couch and a bed.

Density

A measurement of weight over volume that describes the durability and often the firmness of a mattress, expressed in pounds per square foot.

Deep Compression Support

A measure of how well a mattress adapts to a heavy sleeper. These mattresses are usually thicker and have more layers of support.

Double Bed

A bed that measures 54" wide by 75" long, designed for two people, but smaller than Queen and King sizes.

Double-ended Frame

A frame that can use a headboard as well as a footboard.

Double Extra-long

The same width as a Double (54"), but 5" longer (80").

Double Heat Tempering

A process of making innerspring coils more resilient and durable by heating a coil, cooling it, then heating it again.

Dunlop

A foam-making process that creates a foam that's high-density, lower cost, and has progressive compression characteristics.

Durability

How long a mattress will give you support. The average lifespan of a mattress is 7 years, although each type of mattress has a different lifespan.

Dust Mites

Microscopic creatures that live in mattresses and pillows that feed off of dead skin, triggering allergies in many people.

Ease of Repositioning

How easy it is to change positions in bed.

Eastern King

A mattress measuring 76" wide by 80" long, also known as a King.

Edge Breakdown

A loss of support on the outer edge of a bed, which can lead to a person sliding off their bed, or feeling like they're slipping off.

Edge Coils

Additional innerspring coils or stronger coils near the edge of the bed that help prevent edge breakdown.

Edge Support

The ability of a mattress to hold its shape at its edges.

Egyptian Cotton

The climate in Egypt allows cotton fibers to grow extra long. This creates an extra-long staple (ELS) cotton, which is stronger and softer.

Euro-top

Similar to a pillow top, which provides a softer feel to a mattress by adding a padding layer on top of a mattress, but usually denser and higher quality. Instead of being sewn to the top of the mattress, they are sewn flush with the edges of the mattress.

Fatigue

When a mattress can no longer support a person due to the degradation of the material in the mattress (usually coils or foam).

Fiber Filling

Used in bedding, fiber filling is made by exploding polyester fibers into fluffy clusters. It has a similar feel to goose down and is used in pillows and mattress toppers.

Fill Level

The depth of a bladder in a waterbed.

Fire Retardant

Since 2007, all mattresses sold in the U.S. are required to meet a standard for fire-resistance.

Fire Sock

A section that wraps around the core of a mattress that will melt in the event of a fire, and distinguish the fire.

Firmness

How well a mattress stands up to pressure, also referred to as support. Some people require more firmness, and others less, depending on their size, their preferred sleeping positions, and other factors.

Flipping

Turning your mattress over to prevent wear and tear in the same spots. Mattresses can also be rotated for the same purpose.

Foam

An alternative to innerspring mattresses, usually memory foam, polyurethane, or latex.

Foam Core

A section below the top layer of the mattress that acts as the main support system of the mattress.

Foam Encasing

Stiff sections around the outside edge of a foam mattress to help protect against edge breakdown.

Footboard

A board that connects to the foot of a bed frame.

Free Flow

A waterbed with one chamber and no motion dampeners. A common complaint about these beds is that one partner will feel the other partner's movements.

Full

Also known as a standard bed or a double bed, it measures 54" wide by 75" long.

Full Extra-long

5" inches longer than a full, also known as a Double extra-long.

Futon

The Japanese word for "bed," they're made of compressed layers of cotton, wool, or latex. These layers are tufted into place, and futon mattresses are generally only 3 inches thick.

Gauge

The measure of the thickness of a coil inside of an innerspring mattress. Most range between 12 and 17, with the lower number being the thicker measurement, which will result in a firmer spring.

Gusset

A squared-off edge of a pillow, comforter, or upholstery layer that adds strength to the edges.

Headboard

The board that sits at the head of the bed at a 90-degree angle to the mattress.

Helical

Small, spiral-shaped wires that connect coils in an innerspring mattress.

High-density Foam

Foam that is more durable and compresses less than regular foam.

Hybrid Mattress

Usually a combination of an innerspring system to provide support, and foam for its pressure-relieving benefits.

Hydraulic Waterbed

In this mattress, the bladder is divided into smaller compartments where water can travel between compartments through small holes to reduce motion transfer.

Hypoallergenic

Less likely to cause an allergic reaction.

Indentation Force Deflection

Also known as internal load deflection, it's the measurement of the firmness of foam. It's calculated by the amount of force needed to compress foam by 25%. A rating of 14 is considered super plush, and 40-44 is extra firm.

Independent Coils

Coils in an innerspring mattress that work independently of each other to reduce the disturbance of one person's movement for the other.

Inner Quilt

The layer of quilting a pillow top is sewn into.

Innerspring Mattress

A mattress constructed of coil springs surrounded with layers of upholstery to provide a softer sleeping surface. The benefit of these mattresses is that they're usually cheaper, and don't retain body heat through the night, unlike foam mattresses that compress and don't let the heat escape.

King

A mattress that measures 76" wide by 80" long.

King Split

A bed with two Twin Extra Long mattresses measuring 30" wide by 80" long.

Knit

Fabric used in mattress covers that is softer than a woven one.

Loft

A term that describes the height of material or padding.

Low-profile Foundation

A thin foundation to go with an extra-thick mattress so that the total height of the bed is close to a normal bed.

Luxury Mattress

This usually means that a mattress costs $2,000 or more for a Queen size.

Marshall Coil

Also known as encased coils, encased springs, or pocketed springs, these are components of a mattress in which each coil is separately wrapped in a textile material.

Mattress Topper

A topper is a layer of foam or other material that can change the resistance of a mattress, making it softer or firmer.

Memory Foam

Also known as viscoelastic foam, or low-resilience polyurethane foam, it's used in mattresses because it contours to the sleeper, relieving pressure points.

Memory Foam Gel

Gel takes longer to warm up, so when it's added to a foam mattress, it slows the process of the mattress radiating the sleeper's body heat back to them, warming them up and lowering the quality of sleep.

Migration

The displacement of fibers within a mattress over time.

Motion Isolation

The degree to which one person can feel the motion of their partner while lying on a mattress.

Mulesing-Free Wool

The Mulesing procedure is done on Merino sheep to prevent an infection called flystrike. This procedure is said to cause pain in the sheep. Animal rights advocates claim that there are humane alternatives to preventing these infections.

Multi-needle Quilting

A process that uses multiple needles, but still creates a continuous pattern. Also known as continuous quilting.

Murphy Bed

A bed that can be folded up and stored vertically in a cabinet which frees up floor space in a room during the day.

Natural

A meaningless term that has no standards to define it.

No-flip Mattress

A mattress that is only designed to be used one side up. Many mattresses require flipping to last longer, or to maintain their warranty.

Off-gassing

The evaporation of volatile organic compounds in a mattress into the air. Off-gassing is potentially harmful to humans and sometimes will create a chemical smell.

Offset Coil

A type of innerspring mattress coil that has an hourglass shape but is supposed to have better hinging action that a Bonnell coil. These are quieter, conform to the sleeper's body better, and are more expensive.

Olympic Queen

A mattress that's 66" wide by 80" long.

Pedestal

A part of a hard-sided waterbed's foundation.

Polybrominated Diphyenylethers (PBDEs)

A class of chemicals that are flame retardants used in foams and other materials.

Phthalates

A chemical used to soften plastic that has been used in babies' mattresses, but some of which have been banned in products for babies.

Pillow top

A layer that is added to a mattress to make it softer.

Pima Cotton

Similar to Egyptian cotton, it's a generic label applied to cotton grown in the US with an extra-long staple (ELS), making it softer and more durable.

Pincore Holes

Holes in a latex mattress to help soften the mattress.

Platform Bed

Also known as a cabin bed, it's a mattress placed on a foundation.

Plush

A softer surface.

Pocketed Coils

Springs individually wrapped in fabric sleeves, allowing them to react to pressure independently instead of all together, minimizing movement and creating a more buoyant feel.

Pocketed Coils

Innerspring mattress coils that are individually wrapped in separate fabric pockets, providing motion separation.

Posturized

Support added in the center of a mattress to prevent sagging.

Pressure Relief

Pressure relief mattresses help distribute body weight evenly, preventing discomfort that often occurs in the hips and shoulders.

Prorated Warranty

 A mattress warranty that doesn't cover the full price or replacement price after a certain period of time.

Queen

A mattress that measures 60" wide by 80" long.

Queen Split

Two mattresses that are each 30" wide by 80" long.

Quilting

The top layer of a mattress that is part of the cover, adding thickness and softness to the mattress as well as keeping the comfort layers below from shifting.

Recovery Time

How long it takes a piece of foam to return to its original shape after pressure is applied to it.

Recycled Content

When part of a product has been reused.

Recycled Material

Material that has been reprocessed into new material.

Renewable

From sources that are renewed naturally.

Repositioning

Changing sleep positions during the night.

Resiliency

The ability of a material to return to its original position after the pressure that was applied is no longer applied.

Responsiveness

The speed and degree that a mattress responds to motion or pressure.

Safety Liner

The liner that surrounds a bladder in a waterbed in case of a leak.

Sagging

Loss of support in a mattress due to the degradation of the mattress due to age, use, or a poor or broken support beneath the mattress. Sagging often occurs in the center of a mattress.

Self-inflating

An air or foam bed that can be compressed to take up little space, often used by campers.

Semi-Fowler Position

A resting position where the back is at a 45-degree angle to the legs.

Semi-waveless

A waterbed with a bladder that has a small amount of material inside to reduce the movement of water.

Set

A mattress and the foundation, also known as a sleep set.

Single Bed

Also known as a twin bed, it measures 38" wide by 75" long and is the smallest of the adult-sized beds.

Single Extra-long

Also known as a twin extra-long, they measure 38" wide by 80" long, 5" longer than a regular single bed.

Slatted Base

A base to put a mattress on that is made of planks of wood or slats.

Smooth Top

A mattress cover that isn't quilted.

Soft-sided Waterbed

A waterbed that combines elements of a foam mattress by encasing the bladder in foam.

Spring Wire

The wires used to make coils in innerspring mattresses.

Super Single

A mattress that measures 48" wide by 84" long.

Support

The ability of a mattress to hold your spine in a good position while sleeping so that you wake up without stiffness.

Synthetic

Man-made with a chemical process as opposed to occurring in nature.

Talalay

A latex manufacturing process that creates a more consistent firmness than Dunlop latex.

Tape Edge

The seam that runs along the edges of a mattress.

Temperature

How warm a mattress can become during the night. Mattresses that retain heat (this is one of the drawbacks of foam) warm the sleeper and then reduce the quality of sleep.

Tempering

Also called heat-tempering or heat treatment, a process of strengthening innerspring coils by heating them to a high temperature then letting them cool naturally.

Thread Count

The number of threads per square inch in fabric. The higher the thread count, the smoother and finer the fabric, and more expensive.

Ticking

The fabric surface of a mattress or foundation.

Tight Top

A mattress without a pillow top but has a quilted surface.

Torsion Bars

90-degree angle bars inside of a foundation to absorb pressure.

Trial Period

Many mattress retailers will allow you to try a mattress at home for a period of time, such as 90 days, within which you can return it for a full refund.

Trundle Bed

A bed that has a second bed underneath it that can be slid out, making a sleeping space for a second person. These are common in small spaces as they take up less space when not in use.

Tufting

The stitching that holds the padding layers in place.

Twin

A mattress that measures 39" wide by 75" long, also known as a Single.

Twin Extra-long

A mattress that measures 39" long by 80" wide, also known as a Single extra-long.

Upholstery

The soft layers in a mattress that include ticking, quilting, insulation, and cushioning.

Ventilator

Eyelets on the sides of a mattress that allow air to flow in and out.

Volatile Organic Compounds (VOCs)

Products that can off-gas chemicals that are potentially harmful to humans.

Waterbed

A bed that uses water inside of bladders as the core of a mattress, as opposed to foam, gel, or an innerspring system.

Whisper Quiet

A motor or pump for an airbed that is very quiet.

White-glove Delivery

Delivery service where two people will deliver your mattress, set it on its frame, and often take away your old mattress.

Wyoming King

A mattress that's 7' by 7'.