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

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.

Shop Bed Frames

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. 

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.

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

2. Purple Metal Platform

Platform foundations are typically made of wood or metal planks or a grid of metal bars to support a mattress, like the Purple Metal Platform. 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

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

4. Box Springs

Traditional box springs have innersprings and are typically constructed of wood or semi-flex steel. There are other situations where you may need a box spring, including manufacturer requirements and if your frame requires one.

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

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

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

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.

1. Purple Metal Platform

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

The Purple Metal Platform is a sturdy platform with extra slats for shake free, silent and sturdy support.Low profile design to fit any bedroom  

The Purple Platform foundation outranks cheap alternatives because it:

• Prevents squeaking
• Holds up to 2,000 pounds 
• Offers 9 inches of storage space underneath
• Easy to set up

2. Purple Foundation

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

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

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. 

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)