Types of Box Springs: Clearing Up The Coil Confusion

January 7, 2022 | Casper Editorial Team

Stumped over all the different types of box springs? We’ll spring into action to get to the bottom of your questions.

Choosing the right box spring can add support, height, and bounce to your mattress. Using the wrong one can damage your mattress in the long run. It’s helpful to know if you need a box spring, and, if you do, which kinds are available.

In this guide, we’ll walk you through the types of box springs and box spring sizes. Then, we’ll give you six simple steps to choosing the right bed base for you. 

What Is a Box Spring?

A box spring is a type of bed base that serves as a barrier between your mattress and the bed frame. It’s made up of a wooden or metal box with coils inside, all covered in a breathable fabric. 

A box spring’s purpose is to extend the life of your mattress. It does so by absorbing some of the shock and providing more support. It can also add some height to your bed. 

Box springs are a little outdated — newer latex and foam mattresses are more compatible with foundations. However, if you have an innerspring mattress or an antique bed, box springs are still ideal.

Here are some quick pros and cons of box springs.

Box spring pros:

  • Good airflow
  • Light and easy to transport
  • Provides support and shock absorption
  • Good for innerspring mattresses
  • Adds give and bounce

Box spring cons:

  • Not compatible with memory foam or latex mattresses
  • Coils can lose support or break with time
  • Can start to sag after a while
  • Can increase the cost of your bed

But that’s not quite all there is to it. If you’re thinking of buying a box spring, you’ll also need to know the different types out there.

Types of Box Springs

Different types of box springs offer varying heights and inner materials. Here’s an overview of each common type.

Ultra-Low Profile/Bunkie Boards

Say you don’t want to add any additional height to your bed. An ultra-low profile box spring is an ideal choice — it’s only 2 inches high. This thin type of box spring is also sometimes called a bunkie board. They come in all mattress sizes, but are typically used on platform beds or above another box spring to add a tiny layer of support. 

Average height: 2 inches

Who it’s best for: People with thicker mattresses or who don’t want to add more height to their mattress

Low Profile

A low profile box spring is around 4.5 to 5.5 inches in height. This is about half the height of a standard box spring, though both provide a similar amount of support. A low profile option is perfect if you want to add some height — but not too much — to your bed. 

Average height: 4.5-5.5 inches

Who it’s best for: People with thicker mattresses


A standard box spring stands around 8.5 to 9 inches high. This type of box spring is a common choice for added height and support underneath your mattress. 

Average height: 8.5-9 inches inches

Who it’s best for: People want to add some height to their mattress


Traditional box springs have metal coils inside. The coils provide some bounce and give under your mattress. These are most compatible with innerspring mattresses. Newer mattress materials, like memory foam, aren’t designed to work with coil box springs. They’ll need a more supportive foundation. 

Who it’s best for: People who have an innerspring mattress


Zero-deflection box springs are similar to foundations. These bed bases include supportive wooden slats instead of coils. 

Zero-deflection box springs are far more durable than traditional coil box springs. Plus, they work great with modern mattresses like memory foam and latex.  

Who it’s best for: People who have a memory foam or latex mattress

The Casper Foundation can provide the perfect support for years to come. With perfectly placed wooden slats, our Foundation can stand up to years of sleep and can be assembled in minutes — no tools needed. 


Semi-flex box springs have wooden bases with slats, plus metal wires above the slats for added flex and support. They’re usually compatible with all mattress types. Semi-flex box springs are often the most expensive type of box spring you’ll find. 

Who it’s best for: People who have a memory foam or latex mattress who want extra flex and support


Split box springs are just what they sound like: box springs with two halves. 

They’re made in two sections that, when put together, account for the full size of your mattress. The two halves make a split box spring easier to transport. This is especially helpful if you have a queen- or king-sized bed. The halves allow you to easily maneuver the box spring through a narrow hallway or tight corner.

A split box spring is usually more expensive than a standard box spring. They also need support in the middle when they sit on your bed. Make sure your bed frame is built to accommodate a split box spring before buying one. 

Who it’s best for: People with king- or queen-sized mattresses who need to transport the box spring through tight corners or spaces

How To Choose a Box Spring

Now that we’ve covered the different types of box springs, we’ll walk you through choosing one for your bed. If box springs still have you scratching your head, this “how-to” is for you.

1. Use a Box Spring Size Chart To Figure Out the Correct Size

The good thing about choosing a box spring size is that it just needs to match the width and height of your mattress. As long as you know your mattress size, you’re good to go.

Keep in mind that different brands may differ in their dimensions. If you’re not sure, measuring the mattress yourself is never a bad idea. 

Mattress Size of Mattress and Box Spring
Twin 38 x 75 in | 96.5 x 190.5 cm
Twin XL 38 x 80 in | 96.5 x 203 cm
Full 53 x 75 in | 134.5 x 190.5 cm
Queen 60 x 80 in | 152.5 x 203 cm
King 76 x 80 in | 193 x 203 cm
California King 72 x 84 in | 183 x 213 cm
  • Twin —  A twin box spring has the same dimensions as a twin mattress: around 38 x 75 inches.
  • Twin XL —  A twin XL box spring is slightly longer than a twin, measuring 38 x 80 inches.
  • Full  —  A full size box spring has dimensions of 53 x 75 inches.
  • Queen — A queen box spring measures around 60 x 80 inches.
  • King — A king-size box spring is 76 x 80 inches.
  • California King — A California king box spring is around 72 x 84 inches.

2. Decide On a Bed Height

Your bed height will change depending on the box spring you get. If your mattress is already quite tall or you like its current height, go with a low profile box spring that’s only around 5 inches tall. If you don’t mind a taller bed, opt for a standard, 9-inch box spring. 

The height shouldn’t impact your box spring’s support level. Whichever you choose, a box spring will still protect and extend the life of your mattress. 

3. Check the Weight Capacity

You should always confirm the weight capacity of a box spring before purchasing. A box spring should be strong enough to support both your mattress and the people who sleep on it. Factor in your mattress’s firmness as well as the weight of the sleepers. 

4. Consider Materials

Box springs are typically made of wood or metal boxes. They are covered in breathable, skid-resistant fabric and include a dust barrier on the bottom. 

Box springs come in many different materials. If you suffer from bedroom allergies, you might want to seek out a box spring with hypoallergenic fabric. Others are made of organic fabrics. There are also box springs with special additions for added back support.

5. Think About Your Mattress Type

Your mattress type will determine if you need a box spring. Box springs were made specifically for mattresses with coils. So if you have an innerspring mattress, a box spring is an ideal choice. 

However, if you have a memory foam or latex mattress, you should not use a coil box spring. These mattress types are built for stronger support, so they can break down or get damaged over time if placed on top of an incompatible box spring. For modern mattresses, foundations or platform beds are the way to go. 

Similarly, if you have a platform bed, you don’t need a box spring. You can choose to use one for added height, but it’s not necessary. When weighing a platform bed vs. a box spring, remember that a platform bed doesn’t require any kind of added bed base at all.

Check your mattress warranty if you’re not sure what type of bed base will be most compatible. 

Box Spring vs. Alternatives

Box springs are far from the only type of bed base. Here are some other options for your mattress setup.

Box Spring vs. Mattress on the Floor

Most brands will recommend against putting your mattress directly on the floor. Mattresses are built to sit on top of a bed frame or bed base, and placing them on the floor could damage them over time. 

You can, however, place a box spring on the floor with the mattress on top. This will help protect the mattress. Some people choose to do this to save space in small rooms. 

Box Spring vs. Adjustable Bed

An adjustable bed frame goes under your mattress, just like a box spring. The difference is that it has customizable features that allow you to raise the head and foot of the bed, and you’ll need to have a special mattress to go with your adjustable bed frame.

Our adjustable base includes full-body adjustability with features to cater to your individual sleep needs. 

Box Spring vs. Foundation

At this point, you might be wondering if you need a box spring or a foundation

Though box springs are sometimes confused for foundations, they’re not the same thing. Foundations have wooden slats instead of coils. While box springs are light and flexible, foundations can support more weight. Box springs are great for coil mattresses. Foundations are compatible with most other mattress types.

With the Casper Foundation, you can have the best of both worlds. It’s a modern alternative to a box spring with excellent support and easy, no-fuss assembly.

Box Spring vs. Platform Bed

A platform bed is a bed frame that doesn’t require you to use a box spring at all. It’s built to support the mattress on its own. 

If you’re looking for an easy mattress base option, a platform bed could be right for you. The Casper Platform Bed Frame offers stylish support for your bed — no box spring or foundation needed.

With the coil confusion cleared, you can decide how best to support your mattress. At Casper, we’re here to help you find the perfect setup for cozier nights and more restful sleep.