Do I Need a Box Spring or Foundation for My Mattress?
Box springs and foundations are base components designed to support mattresses and protect them from wear. Most box springs and foundations are less expensive than other base types (such as platform beds or adjustable bases), and they also satisfy the warranty requirements of most mattress manufacturers. However, in most cases, you do not necessarily need a box spring or foundation to support your mattress.
What are Box Springs and Foundations, and What Do They Do?
Box springs and foundations support mattresses by providing a buffer between the bottom of the mattress and a bed frame made of metal or wood. In some cases, a box spring or foundation may be placed between the mattress and the floor, as well. The terms ‘box spring’ and ‘foundation’ are often used interchangeably, though both terms are associated with different types of overall construction.
A traditional box spring consists of a wooden frame, steel support springs, and a cloth cover. Some newer models feature frames made of metal, rather than wood. In addition to supporting the mattress, box springs absorb shock from sleeper’s bodies and distribute weight to help prevent wear.
In recent years, foundations have overtaken box springs as the standard mattress base. Rather than springs, foundations feature evenly spaced wooden slats designed to reinforce the mattress and prevent it from crashing through the base; the closer the slats are spaced, the more supportive the platform bed will be. As a result, foundations do not absorb as much shock as box springs. However, they tend to be more suitable for mattresses that require higher levels of support and less weight distribution, such as memory foam and latex models. Foundations, like box springs, are usually encased in cloth.
Box springs and foundations are generally available in three sizes:
Standard (or High-profile)
9 and higher
6 to 8 1/2
15 to 21 1/2
5 1/2 and lower
13 to 14
In order to provide optimal support for the mattress, box springs and foundations are constructed with the same size specifications as mattresses. A general size chart is found below; please note that some manufacturers use slightly different measurements for their mattresses and box springs/foundations.
Box Spring/Foundation Size
38″W x 75L”
Twin Extra Long (XL)
38W” x 80L”
54W” x 75L”
60W” x 80L”
76W” x 80L”
72W” x 84L”
Additionally, some mattresses are available in split Queen, King, or California King models; these consist of two separate mattresses that fit together in the middle to form a complete size. Box springs and foundations may be sold in split models; however, standard box springs and foundations are usually sufficient for split-style Queen, King, or California King mattresses.
Advantages and Disadvantages of Using a Box Spring or Foundation
Some benefits associated with using a box spring or foundation include:
Easier on and off: Due to their height, box springs and foundations allow users to get on and off the bed more easily.
Extended mattress lifespan:Using a box spring or foundation can minimize deterioration and help the mattress last longer.
Minimal sagging:Sagging and indentation is an issue with many mattresses, but box springs offer a flush surface to help the mattress maintain its shape over time.
Lower price-point: Compared to other base types, box springs and foundations tend to be less expensive (see pricing chart below for more information).
There are some notable disadvantages of using a box spring or foundation, as well:
Regular Rotation: Box springs can lose their supportive qualities after too much use, requiring owners to rotate them (which can be tiring and time-consuming).
Occupying Space:Unlike platform beds (see below), box springs do not have any space for personal storage underneath the base.
Extra Costs: Although some box springs may be used on flat floors, many are designed for use with an additional frame or foundation.
Alternatives to Box Springs and Foundations
In addition to box springs or foundations, some mattress brands offer platform beds and/or adjustable bases for mattress support.
A platform bed is designed to support mattresses in the same way as a traditional box spring. Platform beds are constructed with four to six legs. Similar to foundations, platforms feature evenly spaced wooden or metal slats. One advantage of platforms is the extra storage space beneath the bed. Some platforms are not slatted, and instead feature flat sections of wood; these are known as solid platforms.
Some mattress models sold today may also be used with adjustable bases, which allow users to customize how the bed is angled at the foot and/or the head. Adjustable bases are usually equipped with remote or manual controls; the latter tend to be found on less expensive models than the former.
In the case of old box springs or foundations with uneven surfaces, a single section of plywood placed below the mattress can provide a flat surface and extra support. This component is commonly referred to as a ‘bunkie board’.
Finally, some mattress models are advertised as being able to rest on the floor without a foundation. It’s important to read the fine print with these models, as their warranties may still require a solid mattress foundation (see warranty section below for more information).
How Much Do Box Springs, Foundations and Other Bed Bases Cost?
Like mattresses, the cost of a box spring, platform bed or adjustable base will vary by manufacturer. It’s important to note that some mattress brands price their foundations by height, while others price according to size.
The next chart features current size-by-size box spring, platform bed and adjustable base prices from some of the country’s leading mattress manufacturers.
Height Options (Inches)
Bed In a Box
$199 (Twin) to $399 (Split Cali KIng) $100 for Platform Legs
5″ 8″ (Legs Not Included)
$349 (King/California King) $100 for Platform Legs
8″ (Legs Not Included)
$299 (Twin) to $599 (Split Cali KIng) $100 for Platform Legs
5″ 8″ (Legs Not Included)
The Casper Foundation
$250 (Twin, Twin XL, Full) to $350 (King/ Cali King)
$175 (Twin) to $275 (King/Cali King)
$200 (Twin) to $325 (King/Cali King)
Espevär, Slatted (No Legs)
$120 (Twin) to $250 (King)
Espevär, Slatted (Legs)
$145 (Twin) to $300 (King)
7 7/8″ (Legs Not Included)
Espevär, Springs (No Legs)
$180 (Twin) to $330 (King)
Espevär, Springs (Legs)
$205 (Twin) to $380 (King)
7 7/8″ (Legs Not Included)
Purple Platform Base
$129 (Twin XL) to $189 (King/Cali King)
Purple Power Base
$1,399 (Twin XL) to $2,798 (Split King)
Saatva/Loom & Leaf
$250 (Standard Model) $285 (Split Model)
4 3/4″ 8 3/4″
Saatva Adjustable Base
$1,199 (Twin) to $2,498 (King/Cali King)
6″ to 10″ (Adjustable)
$150 (Twin/Twin XL) to $300 (King/Cali King/Split KIngs)
2″ 5″ 9″
$699 (Twin/Twin XL) to $1,398 (King/Cali King/Split Kings)
4 1/2″ 6 1/2″ 9″
$1,199 (Twin/Twin XL) to $2,398 (King/Cali King/Split Kings)
4 1/2″ 6 1/2″ 9″ 12″
$1,899 (Twin/Twin XL) to $3,298 (King/Cali King/Split Kings)
4 1/2″ 6 1/2″ 9″
As the table shows, box springs and foundations tend to be slightly less expensive than platform beds and significantly less expensive than adjustable bases.
The vast majority of mattresses sold today come with warranties that generally range from 10 to 25 years in length. In most cases, the warranty will specify certain types of bases that may — and may not — be used to support the mattress. Specifications vary from brand to brand, but the following guidelines are common in most mattress warranties:
Foundational support: Most mattress warranties allow any type of base — including box springs, foundations, platforms, and adjustable bases — as long as they provide adequate support for both the mattress and its sleepers.
Frame Construction:Although this is not always stressed, some brands require certain types of frames for mattresses based on their size. Commonly, a frame with at least four legs is needed for Twin- and Full-size mattresses; and a frame with five to six legs is needed for Queen-, King- and California-King-size models. Strong center support is also required for all sizes.
Slat dimensions:The warranty may require certain slat measurements if a foundation or platform bed is used to support the mattress. In most cases, slats may not be spaced further than 2 to 3 inches apart.
If a mattress owner does not abide by these terms, then their warranty will be voided if improper foundational support leads to sagging, indentations, or other types of premature wear. It’s important to note that relatively old box springs or foundations — generally speaking, those that have been in use for more than three years — may not provide the ‘adequate support’ listed in mattress warranties. If a claim is filed for a damaged mattress, then the box spring or foundation may be inspected by the manufacturer — and if it is found to be faulty, then the warranty will be voided.
Bottom line: mattress owners do not necessarily need to buy a matching foundation, platform, or adjustable base for their new mattress — but if their original box spring or foundation has been in use for more than three years, then it may not satisfy the support requirements laid out in the mattress warranty.
A box spring, foundation, or other type of base (such as a platform bed or adjustable base) is generally recommended for most mattresses sold today — and in many cases, a suitable base will be required to keep the warranty valid.
If you need to decide whether to purchase a base with your new mattress or continue using your current model, here are a few things to ask yourself:
Have I owned/used the box spring or foundation for more than three years?
Have I experienced sagging, indentations, or other types of wear on my current mattress using the same box spring or foundation?
Are the slats on my foundation evenly spaced to meet the warranty terms of the mattress I want to buy?
Is a new box spring, foundation, or other mattress base in my shopping budget?