What is a Box Spring

December 12, 2023 · Morgan Jackson

What is a Box Spring?

Box springs used to be one of the only options to support your bed, but these days, they’re one of several options available for proper mattress support. Whether or not you want – or need – one will depend on various factors, including your bed frame’s design and the type of mattress you have. Let’s take a closer look at what box springs are and whether you should consider one for your bed.

What is a Box Spring?

A box spring is the same size and shape as a mattress. However, unlike a mattress, a box spring is made with a solid wooden frame. Within the frame, there are metal coils (springs) or a metal grid. The box spring is then covered with fabric. It sits on top of the bed frame and under your mattress.

What Does a Box Spring Do?

A box spring has two primary purposes:  to add height to your bed and to support your mattress. Box springs can vary in height. A “standard” or “average” box spring will be about 9”, while a low profile box spring is closer to 5”. You can even find ultra low profile box springs around 2”, although those tend to be less common. Because of their design, box springs can add extra support for your mattress and years to its lifespan

Box springs also improve airflow through and around your mattress by keeping it off the ground, thus reducing the chances of mold and mildew. Box springs also tend to add a little bit of bounce to your bed.

Like a mattress, a box spring should last 8-10 years.

How Does a Box Spring Compare to a Foundation, Platform Bed, Bunkie Boards, or Slats?

Box springs aren’t the only way to support your mattress. How do the others compare to a box spring?


Foundations are made of a firm frame, like box springs, but foundations have wooden or metal bars that go across the frames instead of metal coils tucked within the frame. Like box springs, they’re also covered in fabric. Foundations generally give an equal amount of support as a box spring but without as much bounce.

Platform Beds

Platform beds are two-in-one: a bed frame and mattress support. As the name suggested, they are made of one solid platform that holds your mattress. They tend to be lower to the ground and may come with drawers at the bottom for storage. Although they tend to be pricier than other mattress supports, they are generally solidly built to give your mattress all the support it needs.

Bunkie Boards

A bunkie board is often used to add additional support. It’s a slab of wood 1-3 inches thick. Bunkie boards can be used on top of another bed frame to add more firmness and mattress support. They’re usually inexpensive and easy to install.

Wooden Slats

Wooden slats are popular forms of support for those on a budget. Because they’re made of wood, they tend to be quieter than box springs. Unlike foundations, they’re not attached to a box or other frame. They’re also easy to move around because they’re more lightweight and usually come already tied together, so all you have to do is unroll them. Some slats can be bought separately; others are made for specific bed frames.

If you want to use wooden slats but you have a memory foam mattress, you may also need to add a bunkie board to provide optimal support for your mattress.

Adjustable Base

An adjustable base is motorized to allow you to customize your bed setup. You can raise or lower your head and feet according to your comfort level. Adjustable bases usually have their own bed frames and support systems.

Do I Need a Box Spring?

To a certain degree, box springs are a matter of preference. Some people enjoy the bouncy-yet-stable firmness of a box spring. Others prefer a foundation that keeps the mattress soft and cushiony. 

Sometimes, a box spring is simply the best choice for mattress support. Some mattress producers will state that their mattress requires a box spring.

Reasons You Might Need a Box Spring

Traditional box springs are helpful for several important reasons. Here are some reasons you might consider a box spring:

  • You want to add height to your bed
  • You have an innerspring mattress
  • You have an older mattress that requires a box spring
  • You have a traditional metal rail bed frame, which requires a box spring to hold up the mattress

Keep in mind that box springs are solidly built and not so flexible; they don’t bend and fold as mattresses do. If you live in an apartment with stairs, or your bedroom is up a flight of stairs, you may not be able to get a box spring to your bedroom, even if you want one.

Reasons You Might Not Need a Box Spring

As purely innerspring mattresses are no longer the only option, many people opt for alternative bed support systems. If any of the following apply, a box spring may not be suitable for you:

  • Your memory foam mattress requires sturdier support, such as a platform bed
  • You prefer the quieter support of wooden slats
  • Your mattress manufacturer provides custom-made support or doesn’t recommend box springs
  • You’re buying support for a sleeper sofa, futon, or bunk bed
  • You have an adjustable base

If you want the height of a box spring, but your mattress manufacturer recommends against one, talk with a Mattress Warehouse Sleep Professional to learn about your best options.

Check Your Mattress Brand

Manufacturers know their mattresses best. They’ll let you know whether a box spring is a good fit for your mattress or whether another type of support would be better suited.

As you shop for your perfect mattress, speak with your mattress professional about the best bed frame and support. They can also help you understand the manufacturer’s warranty and whether it requires you to use a box spring or specifically advises against one.

Shop Mattress Foundations & Box Springs with Mattress Warehouse

When it comes to the best foundation and support for your new mattress, Mattress Warehouse has a wide selection of options for you to choose from. Not sure which one is right for you? Come into our store and speak with a knowledgeable and experienced Mattress Warehouse Sleep Professional today!