Box Spring vs. Foundation: What's the Difference?

Updated: Feb 23

The biggest myth in mattress buying is that you need a box spring. While a supportive surface for your mattress is paramount to its comfort and longevity, there is another option: the foundation. A foundation does the exact same job but lasts longer and provides much better support. As mattress professionals with over 50-years of experience, we’ve learned this first hand. Plus, we want to make sure that every mattress that you buy from us or anyone else is as comfortable, and long-lasting as possible. So, in this guide, we’re going to explain the difference between a box spring and a foundation, answer all your questions and tackle all the false assumptions people have about box springs. Let’s get started.

What is a box spring?

A box spring is a wooden frame with supporting coils or ‘springs’ inside of it. The coils are usually cone-shaped wires, which salespeople will tell you provide flexibility for stiff mattresses, or square coils which they say offers more support. The coils are always located inside the frame, with the top covered in fabric so the mattress can lie directly on top of it.

The box spring is intended to...

- Support the mattress

- To raise the mattress up

- To protect the mattress by absorbing impact

- To improve the airflow of the mattress

For decades, the box spring was touted as a necessary purchase when buying your new mattress. However today, more people know about foundations or sleep on platform beds which replace the need for a box spring. It should also be noted that you should never put a memory foam or hybrid mattress on a box spring, as it does not provide the proper support. Pros of a box spring

- The coils are shock absorbing

- The springs allow for good airflow

- Supports the mattress

- Lifts the mattress up higher

Cons of a box spring

- The coils can be noisy

- The coils can sag and wear over time

- Box springs can only be used with coil mattresses

What is a foundation?

A foundation is basically anything that supports, raises and holds your mattress. Usually, it is made of a wooden frame and slats. Most importantly, it never has springs and provides a much firmer base for your mattress.

The foundation is intended to…

- Support the mattress

- Hold your mattress in the frame

- Raise the mattress up

- Improve the airflow of the mattress

Foundations provide a very solid, firm surface for your bed to rest on which makes it a great choice for people who would normally put their mattress on the floor and those who want to maximize the longevity of their mattress. Usually, people assume that a foundation is only good for a foam or hybrid mattress, but actually, this foundation works well for spring mattresses as well. Pros of a foundation

- Sturdy, even support

- Can be used with any type of mattress

- The most durable

- Good airflow thanks to open slats

Cons of a foundation

- Foundations can be heavy

- Because they are sturdy, they don’t have a lot of give

6 Biggest Assumptions People Make about Box Springs

  1. Box springs last longer This is not the case. Because box springs have coils inside, these can sag and give way over time. When this happens, it can’t properly support your mattress, which can affect how comfortable your mattress is.

  2. Box springs extend the mattress life and make it more comfortable Actually, a solid foundation will last longer, making your mattress last longer and remain more comfortable over time. Box springs have coils inside, which can seem like they would make your bed softer and more comfortable. However, over time the coils inside the box spring will sag and affect the life of your mattress.

  3. Box springs are better for innerspring mattresses Typically, a salesperson will tell you that a box spring is for an innerspring mattress because it has springs that support, and distribute the weight of the mattress evenly. However, an innerspring mattress can be supported by a foundation, too, and this is usually the better option.

  4. You should always use a box spring Nope. Not only is it not necessary to use one on an innerspring mattress, but it can actually affect the comfort and longevity of a memory foam or hybrid mattress. This is because the coils inside of a box spring cannot properly support a memory foam or hybrid mattress, causing the mattress to even feel differently when you lay down on it. Both memory foam and hybrid mattresses are designed to lay on top of the hard, sturdy surface that a foundation supplies.

  5. You should always use a box spring for a spring mattress False. There is a common assumption that if you have a spring mattress, you need to have a matching box spring to support it. Often, mattress retailers will tell you that the springs in the box spring help distribute the weight properly. However, this is not the case. In fact, a foundation provides a much better, more firm structure for your spring mattress.

  6. A box spring is the best way to lift your mattress Not true. Besides providing support, many people think that they need a box spring to lift their mattress higher. The height of a box spring does lift your mattress up to a nice height that makes it easy to get in and out of bed. However, a foundation can also provide the same height you know and love from a box spring. Both box springs and foundations usually sit 6 to 8-inches high. Some of the higher models will come in at 9-inches, and the lower-profile foundation and box springs sit around 4 to 5-inches high.

6 Things People Don’t Know about Mattress Foundations

  1. A foundation can replace a box spring Often, people do not realize that there are alternatives to a box spring. A foundation is a great choice to replace a box spring because it is sturdy and long-lasting. What's more, if you think your box spring isn’t working for you anymore, or you want to try and improve the comfort of your bed, you can easily replace it with a foundation since they are the same size and shape and provide the same lift.

  2. Foundations are more reliable Because the coils in a box spring can sag over time, the solid surface of a foundation actually makes it much more reliable.

  3. A foundation looks just like a box spring What many people don’t realize is that from the outside, a box spring and a foundation look exactly the same. Usually, your bedding will cover your foundation or box spring anyways, so you don’t have to worry about the aesthetics.

  4. Foundations lift your mattress higher The reason many people love using a box spring is that it lifts the mattress up higher so it is easier to get in and out of bed. A foundation can provide the same boost in height as a box spring, usually around 6-inches.

  5. Foundations can be used on all types of beds What is great about a foundation is that it can be used with any type of mattress — whether it is a spring mattress, foam mattress, or hybrid mattress. Foundations are even compatible with custom mattresses and specialty mattresses. Many people wrongly assume something like a round mattress may come standard with a box spring, but this is not the case. Whether you’re buying a niche mattress or a standard queen, a foundation can be a great option.

  6. Foundations can provide great airflow Foundations are made up of slats that usually sit one to three inches apart, which allows for good breathability and airflow for your mattress.

Frequently Asked Questions

Can you tell the difference between a box spring and a foundation?

When looking at a bed frame, you can’t tell if it has a box spring or a foundation on top of it. This is because box springs and foundations are usually housed in wooden boxes. However, you may be able to tell the difference once you are on the bed. A foundation provides a much firmer surface than a box spring, so you may be able to feel the difference when you are on it. You may also be able to tell the difference over time since the springs in a box spring can sag and provide less support over time.

How do you rotate a mattress with a foundation?

Flipping a mattress requires you to lift the mattress up, and turn it around so that where you laid your head before is where you will lay your feet. When you flip your mattress, you don’t have to worry about the foundation since it will stay in place just as it is. On the other hand, if you have a box spring, every time you flip your mattress you should also flip your box spring. This is because just like your mattress, it will wear out in certain spots over time.

Why do salespeople want to sell you a box spring with your mattress?

Often, a salesperson will tell you that a box spring extends the life of your mattress. They may even tell you that without the box spring, your mattress won’t hold up to the warranty.

The reason behind this is that bed frames are usually not sold with any sort of base for you to lay your mattress on. This will cause your mattress to sag over time, and it definitely won’t be as comfortable. However, if you have a platform bed, or you decide to use a foundation instead of a box spring, your mattress will be sturdy and comfortable for years to come.