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What Is a Mattress Foundation? A Guide to Choosing a Bed Foundation

    Last Updated
    September 13, 2023
    min read

    A mattress foundation is a type of bed base. It’s the surface upon which a bed lays, offering support and protection.

    Most buyers assume a mattress is the end-all-be-all for comfort, but the truth is that the foundation is just as critical. 

    What is a mattress foundation? It’s the sturdy, solid surface that goes beneath your bed to provide the proper support a mattress needs. Without adequate support, a mattress tends to sag or creak.

    With so many options, how do you choose the right type of foundation? Read on to learn more about the most common foundations and how to select the right one for you.

    Purple Bed Frames

    Purple's wide range of bed frame options fit any sleep styler and a variety of mattress types.

    What Is a Mattress Foundation?

    A mattress foundation is the stable surface upon which your bed lays. A foundation provides additional support, protects your mattress, and allows airflow that helps cool your bed at night.

    The terms “mattress foundation,” “bed frame,” and “base” are often used interchangeably. However, they are unique parts that make up a bed. 

    • Bed frame: decorative and functional furniture with four sides that suspend a mattress off the floor
    • Mattress base: the structure that a bed lays directly upon and can support a mattress on its own 
    • Mattress foundation: a type of mattress base or the portion of the base, such as slats or planks, that cannot support the bed alone

    A mattress foundation is a type of mattress base. Some foundation types are more commonly referred to as a “base” rather than a foundation — this rings true with an adjustable base. Some types of foundations cannot be used by themselves. For example, you should not place a mattress over a roll of slats or atop a boxspring that lies directly on a bedroom floor. 

    An illustration of a bed shows an arrow pointing to the bed frame and one to the mattress foundation to show the difference between the two parts of a bed.

    While many bed frames come with foundational support in planks or rods, it may not be enough for your specific mattress. This is common in panel bed frames as their wide gaps between slats don’t offer enough support. In this case, you would need to purchase an additional foundation. Be sure to double-check your mattress’s setup and care instructions to determine if extra support is needed.

    Read the FAQ at the bottom of the article for more information specific to different types of mattresses.


    Mattress Foundation Benefits

    A solid mattress foundation has the ability to improve your overall sleep experience. Here are six benefits of a mattress foundation:

    • Improves support: A quality base helps to maintain the shape and integrity of even the most pliable of latex mattresses. In turn, this allows your mattress to provide the proper support your body needs for deep sleep. 
    • Promotes mattress cleanliness: Bed foundations act as a barrier between your mattress and the floor to keep dirt, dust, and other unwanted elements from gathering within and on top of your mattress.
    • Increases mattress lifespan: By providing support and promoting cleanliness, a bed foundation helps extend your mattress’s life.
    • Adds height: A mattress base provides the bed height needed to make getting in and out of bed easier.
    • Increases airflow: Bed foundations allow for airflow above and below the mattress, helping to keep you cool while you sleep.
    • Prevents mattress sliding: ​​A proper bed foundation prevents mattresses from sliding as you move throughout the night. 

    Types of Mattress Foundations 

    Most mattresses have a complementary base that provides the proper support and keeps them in place. Here are some of the most common bed foundations and their corresponding mattresses.

    A graphic shows six types of mattress foundations with illustrations of each.

    1. Adjustable Bed Base

    Also known as a power base, an adjustable bed base moves and flexes to accommodate any sleeping style. Adjustable bed bases are typically electronic metal frames that allow you to lay at an incline or with your feet and legs elevated. Many adjustable bases can be placed within a bed frame by using the adjustable height legs or zero clearance feature.

    Adjustable bases can be particularly helpful for customizing comfort to improve your sleep and health while elevating your everyday lifestyle, whether spent working or watching television from bed.

    Ideal Sleeper:

    • Those who use their bed for other activities outside of sleep (i.e. work, reading, etc.)
    • Those who find an elevated position improves overnight comfort and, therefore, better sleep
    • People who struggle with snoring
    • Sleepers who need extra help with getting in and out of bed more easily

    Ideal Mattress Type:

    • Memory foam
    • Latex
    • Some hybrid and innerspring mattresses



    Adjustable comfort 

    Requires a flexible mattress

    Health benefits

    Heavy and difficult to move

    Can be used with or without an additional bed frame for a fully furnished look

    Most expensive to purchase and maintain

    2. Platform Base

    Platform foundations are typically made of wood or metal planks or a grid of metal bars to support a mattress, like the Purple Platform Bed Frame. Platform bases already have foundational support built into their design and do not require extra slats or a box spring.

    This pared-down option is engineered to exact measurements of standard mattress sizes. Platform beds often sit higher, allowing extra storage space underneath.

    Ideal Mattress Type:

    • Memory foam
    • Latex
    • Hybrid
    • Innerspring
    • Some air mattresses
    • Some water beds



    Does not require a box spring or flat foundation

    Metal may be noisy 

    Mattresses lay directly on the platform bed frame, which usually has slats


    Offers a more modern, low-profile aesthetic 


    3. Flat Foundations

    Modern box springs, often called flat foundations, are similar to box springs in appearance and aesthetic but are simply just a metal or wood box covered with fabric, no springs included. With no springs, flat foundations can be used with most mattress types.

    Flat foundations are ideal for:

    • Tall individuals looking to add height to their bed
    • Panel bed frames with an open design or wide gaps between support rails

    Ideal Mattress Type:

    • Memory foam 
    • Latex 
    • Hybrid



    High-quality flat foundations provide great support for mattress longevity

    Product lifespan is about 10 years

    High weight limits


    4. Box Springs

    Traditional box springs have innersprings and are typically constructed of wood or semi-flex steel. 

    Box springs are almost always paired with innerspring mattresses. In most cases, memory foam beds, latex, hybrid, and Purple mattresses shouldn’t be used with box spring foundations. The coils in a traditional box spring can damage these beds over time. 

    Box springs are ideal for:

    • Tall individuals looking for a bed that’s not low to the ground
    • Panel bed frames with an open design or wide gaps between support rails

    Ideal Mattress Type:

    • Innerspring mattresses



    May be included in the price of an innerspring mattress


    Extra bounce to absorb pressure (if made with coils)

    Expensive to purchase separately or to upgrade to a split box spring


    Can make a bed very high off the ground even with a low-profile option


    Product lifespan is about 10 years

    READ MORE: Bed Slats vs Box Springs

    5. Bed Slats

    A slatted foundation is a set of long solid wood inside a bed frame. Slats are an inexpensive and straightforward solution for proper bed support. They also provide added air circulation, meaning cooler sleep.

    Bed slats should be no more than 3 inches apart from one another and each slat should be about 2.5 to 3.5 inches wide and 1 inch tall. These measurements ensure your mattress gets the support it requires while preventing sag over time. Narrow slats may offer more air circulation but less support. Be sure to check your slatted mattress foundation's spacing regularly to avoid damaging your mattress

    Many bed frames come with a built-in slatted foundation, though the option to buy slats separately means you don’t have to buy an entire frame if a slat breaks. Rolled slats are a common option that are easy to assemble and store and more likely to stay in proper placement over time.

    Ideal Mattress Type:

    • Memory foam
    • Latex
    • Most hybrids
    • Most innersprings



    Low cost

    Narrow slats are best to provide optimal support

    Easy to set up

    Potential for sagging if slats are too far apart

    Easy to replace

    Potential for shifting

    6. Bunkie Boards

    A bunkie board is a 1- to 3-inch flat barrier, usually made of wood, plywood, or particleboard, designed to fit between your mattress and the bed frame it rests on. While they offer additional support and firmness, it comes at the cost of blocked airflow. 

    Bunkie boards are ideal for:

    • Bunk beds
    • Children's beds, like floor beds
    • Sleepers who don't want extra height for their mattress
    • Panel bed frames with an open design or wide gaps between support rails

    Ideal Mattress Type:

    • All mattress types



    Low profile support

    Prevents airflow

    Simple option that works with most mattresses and bed frames

    Not ideal for humid areas due to the potential for mold and warping

    Purple Mattress Foundations

    The right bed frame can dramatically improve your sleep experience. Because we understand that bed foundations carry great weight in the quality of your sleep, Purple offers several high-quality bed frames designed for all mattress types and room styles. All of our mattress foundations can be used with or without an additional bed frame.



    Best For


    Key Features

    Purple Platform Bed Frame

    Tight spaces

    Sleepers looking for an affordable bed frame

    Twin: $159

    Twin XL: $169

    Full: $189

    Queen: $199

    King: $229

    Cal king: $229

    Easy to set up

    No-squeak design

    13” of storage space underneath

    Comes with headboard mounting hardware 

    Supports up to 2,000 pounds

    Purple Foundation

    Sleepers looking for an upholstered bed frame

    Twin: $415

    Twin XL: $435

    Full: $475

    Queen: $495 

    King: $595

    Cal king: $595

    Sets up quickly

    Supports any mattress

    Available in charcoal grey and stone grey

    Headboard can be purchased separately or as a bed frame set

    Holds up to 2,000 pounds

    Purple Premium Smart Base

    Sleepers looking for an affordable adjustable bed frame

    Twin: $995

    Queen: $1,195

    King: $1,595

    Cal king: $1,595

    Split king: $1,990

    2 adjustable zones

    4 pre-programmed position presets

    Adjustable leg height

    Wireless remote or app control

    Purple Premium Plus Smart Base

    Ultimate comfort and luxury

    Twin: $1,595

    Queen: $1,895

    King: $2,595

    Cal king: $2,595

    Split king: $3,190

    4 adjustable zones


    3 custom position presets

    3  pre-programmed position presets

    Remote or app control

    Adjustable leg height

    Holds up to 750 pounds

    1. Purple Platform Bed Frame

    The metal Purple Platform Bed Frame lays flat before a light purple background.

    Best for: Tight spaces or sleepers looking for an affordable bed frame

    The Purple Platform Bed Frame is a minimalist, sturdy, and storage-friendly way to elevate your mattress. It’s quick and easy to set up — it only takes a few minutes, and no tools are required. All you have to do is unfold it, snap the legs into place, and you’re ready to get a great night’s sleep. 

    The Purple Platform foundation outranks cheap alternatives because it:

    • Prevents squeaking with its polypropylene buffer design
    • Holds up to 2,000 pounds 
    • Offers 13 inches of storage space underneath
    • Comes with mounting hardware compatible with most headboards

    2. Purple Foundation

    The Purple Foundation in stone grey shown with the matching headboard before a light purple background.

    Best for: Sleepers looking for an upholstered bed frame

    The Purple Foundation features a versatile grey fabric and tapered wooden legs for a sophisticated, mid-century modern look. The neutral design pairs well with most bedroom aesthetics.

    This flat foundation is easy to assemble — without any tools required. But don’t let that fool you — the Purple Foundation is exceptionally strong and durable. It’s built with polyethylene slats and nylon buffers that don’t creak or crack.

    Here are a few more highlights about the Purple Bed Frame:

    • Holds up to 2,000 pounds
    • Sets up quickly
    • Supports any mattress
    • Available in charcoal grey and stone grey
    • Headboard can be purchased separately or as a set with the Purple Bed Frame

    3. Purple Premium Smart Base

    The charcoal gray Purple Premium Smart Base in an inclined position before a light purple background.

    Best for: Sleepers looking for an affordable adjustable bed frame

    Designed to help improve sleep quality and daily comfort, the Purple Premium Smart Base provides adjustable support for your mattress at an affordable price. It’s programmed with four presets that allow you to change positions with just one click of a button.

    • The Lounge preset allows you to get work done from the comfort of your bed. 
    • Zero-Gravity offers a near-weightless feel while you sleep.
    • Anti-Snoring mode slightly elevates the head to quiet sleep interruptions.
    • One Touch Flat brings you back to a flat position with ease.

    With the Purple Premium Smart Base, you’ll have:

    • 2 adjustable zones (head and foot elevation)
    • 3 pre-programmed position presets
    • Adjustable leg height
    • Wireless remote or app control

    4. Purple Premium Plus Smart Base

    The charcoal gray Purple Premium Plus Smart Base in an inclined position before a light purple background.

    Best for: Ultimate comfort and luxury

    The Purple Premium Plus Smart Base offers all the features of the Premium Smart Base plus several additional comfort features. It has two additional adjustable zones (Pillow Tilt and Lumbar Support) and dual-zone massaging to reach peak relaxation.

    The key features of the Purple Premium Plus Smart Base are:

    • 4 adjustable zones, including neck and lumbar
    • 3 pre-programmed position presets and three custom preset buttons
    • Motion-sensored under-bed lighting
    • Holds up to 750 pounds

    How To Choose the Best Mattress Foundation 

    Choosing the right foundation for you involves many factors, from your preferred mattress type to budget. Here’s what to consider before deciding on a bed foundation.

    1. Consider Mattress Type and Size

    Your mattress plays a crucial role in the bed foundation that will suit you best. When replacing bedroom furniture, it’s best to buy the bed foundation and frame that suits your mattress, not the other way around. First, pick the best mattress type for your typical sleeping position, then decide on the complementary bed frame that provides proper support.

    Most bed foundations will work with any mattress type, though, to be safe, reference the graphic below of the ideal mattress and foundation pairings. 

    A chart shows which foundation to use for each type of mattress.

    Most bed foundations can be paired with most mattress sizes unless you have a specialty size, such as an Alaskan king bed, which may require a custom-built frame.

    2. Set Your Budget

    Identifying a budget for a bed frame is important when you begin looking. Generally, adjustable bed frames and platform foundations fall within a higher price range, while slatted mattress foundations or bunkie boards are less expensive. The most inexpensive option may not always be the best, so weigh the pros and cons.

    READ MORE: Best Time To Buy a Mattress

    3. Assess the Durability

    Most adjustable bases and some bed frames include weight capacities in their product specifications. Weight capacity identifies the specific weight — including mattress, bedding, and sleepers with even distribution — a bed frame or base is built to support.

    4. Review the Assembly Requirements

    Nobody wants to struggle with bed frame assembly, so take a bit of time to decide if you can assemble your unit by yourself or will require help. This is especially important if you move often, as you’ll have to take apart the base and frame.

    5. Choose Your Style and Design Preference

    Many people consider a bed frame’s design to be one of the most important factors when choosing a unit. Depending on the foundation you choose, you may or may not need a separate bed frame — it just depends on your preferred aesthetic.

    Visualize how your foundation will look with your other bedroom fixtures and furniture. You may also want to match your windows and doors' metal and wood finishes to those of your bed foundation.

    6. Read the Warranty

    Most mattress warranties will outline appropriate bed foundations as well as which ones will void the warranty. For example, Purple mattresses do not work with box springs, and using one will void your warranty. Be sure to check the warranty label before buying if you plan to use a prior base with a new mattress. 

    When To Replace Your Mattress Foundation

    It’s not always necessary to purchase a new foundation with the acquisition of a new mattress. Identifying their compatibility and the condition of your current foundation will be the determining factor. 

    You should purchase a new base for your bed in the following scenarios:

    • Parts are loose and cannot be tightened
    • Parts are cracked, broken, or stop working
    • Protective fabric is ripped or has holes (for box springs)
    • Your mattress sags or dips even though it’s relatively new
    • Your mattress moves around or won’t stay in place
    • Your new mattress doesn’t pair well with your old foundation (i.e., you upgrade to a hybrid mattress from an innerspring and only have a panel bed frame)

    How long your mattress foundation will last depends on its type, materials, how much daily weight it supports, and how much activity it sees. On average, this is when you should replace your foundation based on which type you have:

    • Adjustable Base: 15+ years when regularly serviced
    • Platform Bed: 15+ years (though you may need to follow the replacement recommendations for slats if made of wood)
    • Flat Foundation: 10 years
    • Box Spring: 10 years or with each new mattress purchase as it’s not recommended to use an old box spring with a new mattress
    • Slats: 7 to 10 years for wood
    • Bunkie Board: 2 to 3 years depending on the material (metal lasts the longest)



    A mattress foundation provides additional support and protection for a mattress. Foundations prevent mattresses from sagging and sliding while slowing wear and promoting cleanliness. Depending on the foundation, they can also add height to your bed.

    A mattress foundation doesn’t replace a box spring because box springs and foundations are one and the same. A box spring is a type of mattress foundation made primarily for innerspring mattresses.

    A mattress foundation is the part of a bed frame that a mattress lays upon and supports. Most mattress foundations are not a solution alone — only platform adjustable beds do not need a separate bed frame. The bed frame typically lifts the mattress from the ground and is more decorative.

    It’s not advised to sleep with a mattress directly on the floor. The floor may provide support, but it also prohibits airflow, provides easy access to bugs and pests, and traps heat, dust, and other bacteria. You should always use a Purple mattress with the appropriate base and never place it on the floor.

    If you’re placing an adjustable base or platform bed inside a decorative frame, opt for one with solid wood or upholstered sides that meet the floor. These frames can easily hide the metal legs of a mattress foundation. 

    Still asking yourself, “Do I need an additional foundation for my mattress?” In short, most mattresses require a foundation. Your bed frame may or may not already have adequate support, so here are a few cases of when you should consider buying a mattress foundation.

    • You own an innerspring mattress. You need a box spring.
    • Your bed frame has no inner support structures. You need slats, a bunkie board, or a platform frame.
    • You have a panel bed, or your frame’s planks are more than three inches apart. You need a bunkie board, new slats, or a box spring (for innerspring mattresses only).
    • You want to sleep with your head or feet elevated. You need an adjustable base.

    There are many different kinds of mattress foundations, and they all have differences regarding airflow, ease of assembly, and durability. Choosing the right one can give your mattress a much-needed support system and, in turn, may comfortably support your body weight.

    Not sure which bed base dimension you need? Check out our mattress foundation size guide

    About the authors

    April Seifert

    April has nearly a decade of writing experience, with 3+ years specializing in sleep content. Her work has been covered by sites like BuzzFeed, Entrepreneur, and Money Under 30. She has an M.A. in Magazine, Newspaper, and Online Journalism from Syracuse University and a B.A. in Communication Studies. As a self-proclaimed expert in all things cozy, she sleeps better at night, knowing her writing helps others sleep in comfort, too.

    Brooke Reynolds
    Senior Product Manager of Bases and Smart Comfort

    Brooke Reynolds is a Senior product manager of bases and smart comfort at Purple. She's passionate about designing bases specifically to support Purple mattresses and educating customers on how adjustable bases can improve sleep, provide targeted support and enhance your bedtime routine.