If you’re on a quest for the perfect mattress, you’ve probably already realized that it isn’t just about the mattress. What’s underneath, whether a box spring or foundation, is practically just as important as the mattress itself. Every mattress needs proper support to increase its longevity.

Sleep is a physiological function, just like breathing, and it is essential to your entire well-being. When we asked people who sleep less than eight hours a night why that was the case, 49.1% said it was due to a bad mattress. It’s safe to say that the wrong mattress or the wrong mattress support can be life-altering. 

So, what’s the difference between a box spring and a foundation, and what are the pros and cons of each? Let’s dive in. 

What is a Box Spring?

Most commonly used with innerspring mattresses, a box spring is a mattress support system made out of springs, cloth and wood. Essentially, it’s a cloth-covered wooden box with springs inside and should be the same size as the mattress it supports. In addition to providing stability and support, think of a box spring as a mattress shock absorber that helps to absorb some of the impacts a mattress might receive throughout time. 

If you have an innerspring mattress (though box springs can work with other mattress types as well), want a firm support system, want to prevent mattress sagging, and want to be a bit more elevated off the floor: a box spring may be the right support system for your new mattress. 

Pros and Cons of a Box Spring


  • Reduces mattress wear and tear by providing shock absorbency
  • Keeps a mattress off the floor, reducing dirt, dust and other allergen exposure
  • Provides firm support to a mattress to help prevent sagging
  • Can usually be purchased as a set with the mattress


  • Can become a comfortable host of dust mites and insects if not replaced regularly
  • Can break down over time and need to be replaced
  • Not the optimal choice for every mattress type

What is a Foundation?

A foundation is another type of mattress support system. The most common foundations are made of wood, metal or a wood/metal hybrid. This is a flat wooden board or wooden slats and is sometimes covered in fabric. A foundation is often placed in a bed frame to provide sturdy mattress support but can be placed on the floor if preferred. Foundations are similar, in functionality, to a platform bed. 

If you’re looking for versatility in mattress options and a super firm night’s sleep and don’t mind a bit of assembly, a foundation may be the best option for you. 

Pros and Cons of a Foundation


  • Works well for nearly any mattress type
  • Great for people living in small spaces
  • Keeps a mattress off the floor, reducing dirt, dust and other allergen exposure
  • Provides firm support to prevent mattress sagging
  • Can usually be purchased from the mattress manufacturer


  • Can be too firm for some sleepers
  • Often heavy and difficult to move
  • Often more expensive than a box spring

Box Spring vs. Foundation

While you’re testing out new mattresses in-store or reading about the top-rated mattresses online, don’t forget about your mattress support system. It’s so important that many manufacturers will not honor the mattress warranty if you don’t have one. 

When the choice comes down to foundation vs. box spring, it’s important to recognize that there are some similarities but also some significant differences. Both options are typically at least partially constructed of wood, can be placed in a bed frame or on the floor, help prevent mattress wear and tear, and are often available to purchase wherever you’re buying a mattress. 

But it’s really the differences between box springs and foundations that will help make your final decision. If you want the versatility of being able to choose pretty much any mattress type, like a super firm support system, and won’t have an issue with a bit of a heavier moving situation, then a foundation may be a stellar choice. But if you’re more of a traditional innerspring bed type, like firm but not super firm support, and don’t mind replacing to avoid breakdown, a box spring and your new mattress may be the perfect union. 

Frequently Asked Questions

Is a foundation the same as a box spring?

No. Some people refer to a box spring as a type of foundation, but a true foundation differs from a box spring in that a foundation is typically wood, metal or a combination of both and has a flat wood surface or a slatted surface for the mattress. A box spring is also partially made of wood but contains springs or coils for mattress support. Both are considered mattress support systems. 

Is a box spring necessary?

Unless you have a platform build that has its own built-in foundation, some sort of mattress support system is necessary, whether box spring or foundation. If you’ve invested in a new mattress, you may void your warranty if you bypass a box spring or foundation.

Can you just buy a box spring?

Yes. If you already have a mattress and just need to purchase a box spring, you should be able to purchase one from any mattress retailer. Just be sure to buy the same size. For example, if you have a queen mattress, you’ll also need a queen box spring.

Are metal or wood box springs better?

The only metal contained in a box spring is in the springs or coils. The frame of the box spring is typically constructed from wood. You can, however, purchase metal bed frames to support the box spring and mattress.